6 Jim Tcl v0.73 - overview of the Jim tool command language facilities
16 jimsh -e '<immediate-script>'
21 * <<CommandIndex,Command Reference>>
22 * <<OperatorPrecedence,Operator Precedence>>
23 * <<BuiltinVariables, Builtin Variables>>
24 * <<BackslashSequences, Backslash Sequences>>
28 Jim is a reimplementation of Tcl, combining some features from
29 earlier, smaller versions of Tcl (6.x) as well as more modern
30 features from later versions of Tcl (7.x, 8.x). It also has some some
31 entirely new features not available in any version of Tcl.
33 This version is about double the size of "tinytcl" (6.8), depending upon
34 the features selected, but is significantly faster and has many new features.
36 Note that most of this man page is the original 6.8 Tcl man page, with
37 changes made for differences with Jim.
39 The major differences with Tcl 8.5/8.6 are:
41 1. Object-based I/O (aio), but with a Tcl-compatibility layer
42 2. I/O: Support for sockets and pipes including udp, unix domain sockets and IPv6
44 4. Support for references (`ref`/`getref`/`setref`) and garbage collection
45 5. Builtin dictionary type (`dict`) with some limitations compared to Tcl 8.6
46 6. `env` command to access environment variables
47 7. `os.fork`, `os.wait`, `os.uptime`, `rand`
48 8. Much better error reporting. `info stacktrace` as a replacement for '$errorInfo', '$errorCode'
49 9. Support for "static" variables in procedures
50 10. Namespaces, threads and coroutines are not support
51 11. Command and variable traces are not supported
52 12. Direct command line editing rather than the `history` command
53 13. Expression shorthand syntax: +$(...)+
58 Changes between 0.72 and 0.73
59 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
60 1. Built-in regexp now support non-capturing parentheses: (?:...)
61 2. Add `string replace`
62 3. Add `string totitle`
64 5. Add +build-jim-ext+ for easy separate building of loadable modules (extensions)
65 6. `local` now works with any command, not just procs
66 7. Add `info alias` to access the target of an alias
68 Changes between 0.71 and 0.72
69 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
70 1. procs now allow 'args' and optional parameters in any position
71 2. Add Tcl-compatible expr functions, `rand()`, `srand()` and `pow()`
72 3. Add support for the '-force' option to `file delete`
73 4. Better diagnostics when `source` fails to load a script with a missing quote or bracket
74 5. New +tcl_platform(pathSeparator)+
75 6. Add support settings the modification time with `file mtime`
76 7. `exec` is now fully supported on win32 (mingw32)
77 8. `file join`, `pwd`, `glob` etc. now work for mingw32
78 9. Line editing is now supported for the win32 console (mingw32)
79 10. Add `aio listen` command
81 Changes between 0.70 and 0.71
82 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
83 1. Allow 'args' to be renamed in procs
84 2. Add +$(...)+ shorthand syntax for expressions
85 3. Add automatic reference variables in procs with +&var+ syntax
86 4. Support +jimsh --version+
87 5. Additional variables in +tcl_platform()+
88 6. `local` procs now push existing commands and `upcall` can call them
89 7. Add `loop` command (TclX compatible)
90 8. Add `aio buffering` command
91 9. `info complete` can now return the missing character
92 10. `binary format` and `binary scan` are now (optionally) supported
93 11. Add `string byterange`
94 12. Built-in regexp now support non-greedy repetition (*?, +?, ??)
96 Changes between 0.63 and 0.70
97 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
98 1. +platform_tcl()+ settings are now automatically determined
99 2. Add aio `$handle filename`
100 3. Add `info channels`
101 4. The 'bio' extension is gone. Now `aio` supports 'copyto'.
102 5. Add `exists` command
103 6. Add the pure-Tcl 'oo' extension
104 7. The `exec` command now only uses vfork(), not fork()
105 8. Unit test framework is less verbose and more Tcl-compatible
106 9. Optional UTF-8 support
107 10. Optional built-in regexp engine for better Tcl compatibility and UTF-8 support
108 11. Command line editing in interactive mode, e.g. 'jimsh'
112 Tcl stands for 'tool command language' and is pronounced 'tickle.'
113 It is actually two things: a language and a library.
115 First, Tcl is a simple textual language, intended primarily for
116 issuing commands to interactive programs such as text editors,
117 debuggers, illustrators, and shells. It has a simple syntax and is also
118 programmable, so Tcl users can write command procedures to provide more
119 powerful commands than those in the built-in set.
121 Second, Tcl is a library package that can be embedded in application
122 programs. The Tcl library consists of a parser for the Tcl language,
123 routines to implement the Tcl built-in commands, and procedures that
124 allow each application to extend Tcl with additional commands specific
125 to that application. The application program generates Tcl commands and
126 passes them to the Tcl parser for execution. Commands may be generated
127 by reading characters from an input source, or by associating command
128 strings with elements of the application's user interface, such as menu
129 entries, buttons, or keystrokes.
131 When the Tcl library receives commands it parses them into component
132 fields and executes built-in commands directly. For commands implemented
133 by the application, Tcl calls back to the application to execute the
134 commands. In many cases commands will invoke recursive invocations of the
135 Tcl interpreter by passing in additional strings to execute (procedures,
136 looping commands, and conditional commands all work in this way).
138 An application program gains three advantages by using Tcl for its command
139 language. First, Tcl provides a standard syntax: once users know Tcl,
140 they will be able to issue commands easily to any Tcl-based application.
141 Second, Tcl provides programmability. All a Tcl application needs
142 to do is to implement a few application-specific low-level commands.
143 Tcl provides many utility commands plus a general programming interface
144 for building up complex command procedures. By using Tcl, applications
145 need not re-implement these features.
147 Third, Tcl can be used as a common language for communicating between
148 applications. Inter-application communication is not built into the
149 Tcl core described here, but various add-on libraries, such as the Tk
150 toolkit, allow applications to issue commands to each other. This makes
151 it possible for applications to work together in much more powerful ways
152 than was previously possible.
154 Fourth, Jim Tcl includes a command processor, +jimsh+, which can be
155 used to run standalone Tcl scripts, or to run Tcl commands interactively.
157 This manual page focuses primarily on the Tcl language. It describes
158 the language syntax and the built-in commands that will be available
159 in any application based on Tcl. The individual library procedures are
160 described in more detail in separate manual pages, one per procedure.
162 JIMSH COMMAND INTERPRETER
163 -------------------------
164 A simple, but powerful command processor, +jimsh+, is part of Jim Tcl.
165 It may be invoked in interactive mode as:
169 or to process the Tcl script in a file with:
173 It may also be invoked to execute an immediate script with:
179 Interactive mode reads Tcl commands from standard input, evaluates
180 those commands and prints the results.
183 Welcome to Jim version 0.71, Copyright (c) 2005-8 Salvatore Sanfilippo
186 . lsort [info commands p*]
187 package parray pid popen proc puts pwd
188 . foreach i {a b c} {
195 invalid command name "bad"
199 If +jimsh+ is configured with line editing (it is by default) and a VT-100-compatible
200 terminal is detected, Emacs-style line editing commands are available, including:
201 arrow keys, +\^W+ to erase a word, +\^U+ to erase the line, +^R+ for reverse incremental search
202 in history. Additionally, the +h+ command may be used to display the command history.
204 Command line history is automatically saved and loaded from +~/.jim_history+
206 In interactive mode, +jimsh+ automatically runs the script +~/.jimrc+ at startup
211 The central data structure in Tcl is an interpreter (C type 'Jim_Interp').
212 An interpreter consists of a set of command bindings, a set of variable
213 values, and a few other miscellaneous pieces of state. Each Tcl command
214 is interpreted in the context of a particular interpreter.
216 Some Tcl-based applications will maintain multiple interpreters
217 simultaneously, each associated with a different widget or portion of
218 the application. Interpreters are relatively lightweight structures.
219 They can be created and deleted quickly, so application programmers should
220 feel free to use multiple interpreters if that simplifies the application.
224 Tcl supports only one type of data: strings. All commands, all arguments
225 to commands, all command results, and all variable values are strings.
227 Where commands require numeric arguments or return numeric results,
228 the arguments and results are passed as strings. Many commands expect
229 their string arguments to have certain formats, but this interpretation
230 is up to the individual commands. For example, arguments often contain
231 Tcl command strings, which may get executed as part of the commands.
232 The easiest way to understand the Tcl interpreter is to remember that
233 everything is just an operation on a string. In many cases Tcl constructs
234 will look similar to more structured constructs from other languages.
235 However, the Tcl constructs are not structured at all; they are just
236 strings of characters, and this gives them a different behaviour than
237 the structures they may look like.
239 Although the exact interpretation of a Tcl string depends on who is doing
240 the interpretation, there are three common forms that strings take:
241 commands, expressions, and lists. The major sections below discuss
242 these three forms in more detail.
246 The Tcl language has syntactic similarities to both the Unix shells
247 and Lisp. However, the interpretation of commands is different
248 in Tcl than in either of those other two systems.
249 A Tcl command string consists of one or more commands separated
250 by newline characters or semi-colons.
251 Each command consists of a collection of fields separated by
252 white space (spaces or tabs).
253 The first field must be the name of a command, and the
254 additional fields, if any, are arguments that will be passed to
255 that command. For example, the command:
259 has three fields: the first, `set`, is the name of a Tcl command, and
260 the last two, 'a' and '22', will be passed as arguments to
261 the `set` command. The command name may refer either to a built-in
262 Tcl command, an application-specific command bound in with the library
263 procedure 'Jim_CreateCommand', or a command procedure defined with the
264 `proc` built-in command.
266 Arguments are passed literally as text strings. Individual commands may
267 interpret those strings in any fashion they wish. The `set` command,
268 for example, will treat its first argument as the name of a variable
269 and its second argument as a string value to assign to that variable.
270 For other commands arguments may be interpreted as integers, lists,
271 file names, or Tcl commands.
273 Command names should normally be typed completely (e.g. no abbreviations).
274 However, if the Tcl interpreter cannot locate a command it invokes a
275 special command named `unknown` which attempts to find or create the
278 For example, at many sites `unknown` will search through library
279 directories for the desired command and create it as a Tcl procedure if
280 it is found. The `unknown` command often provides automatic completion
281 of abbreviated commands, but usually only for commands that were typed
284 It's probably a bad idea to use abbreviations in command scripts and
285 other forms that will be re-used over time: changes to the command set
286 may cause abbreviations to become ambiguous, resulting in scripts that
291 If the first non-blank character in a command is +\#+, then everything
292 from the +#+ up through the next newline character is treated as
293 a comment and ignored. When comments are embedded inside nested
294 commands (e.g. fields enclosed in braces) they must have properly-matched
295 braces (this is necessary because when Tcl parses the top-level command
296 it doesn't yet know that the nested field will be used as a command so
297 it cannot process the nested comment character as a comment).
299 GROUPING ARGUMENTS WITH DOUBLE-QUOTES
300 -------------------------------------
301 Normally each argument field ends at the next white space, but
302 double-quotes may be used to create arguments with embedded space.
304 If an argument field begins with a double-quote, then the argument isn't
305 terminated by white space (including newlines) or a semi-colon (see below
306 for information on semi-colons); instead it ends at the next double-quote
307 character. The double-quotes are not included in the resulting argument.
308 For example, the command
310 set a "This is a single argument"
312 will pass two arguments to `set`: 'a' and 'This is a single argument'.
314 Within double-quotes, command substitutions, variable substitutions,
315 and backslash substitutions still occur, as described below. If the
316 first character of a command field is not a quote, then quotes receive
317 no special interpretation in the parsing of that field.
319 GROUPING ARGUMENTS WITH BRACES
320 ------------------------------
321 Curly braces may also be used for grouping arguments. They are similar
322 to quotes except for two differences. First, they nest; this makes them
323 easier to use for complicated arguments like nested Tcl command strings.
324 Second, the substitutions described below for commands, variables, and
325 backslashes do *not* occur in arguments enclosed in braces, so braces
326 can be used to prevent substitutions where they are undesirable.
328 If an argument field begins with a left brace, then the argument ends
329 at the matching right brace. Tcl will strip off the outermost layer
330 of braces and pass the information between the braces to the command
331 without any further modification. For example, in the command
333 set a {xyz a {b c d}}
335 the `set` command will receive two arguments: 'a'
338 When braces or quotes are in effect, the matching brace or quote need
339 not be on the same line as the starting quote or brace; in this case
340 the newline will be included in the argument field along with any other
341 characters up to the matching brace or quote. For example, the `eval`
342 command takes one argument, which is a command string; `eval` invokes
343 the Tcl interpreter to execute the command string. The command
350 will assign the value '22' to 'a' and '33' to 'b'.
352 If the first character of a command field is not a left
353 brace, then neither left nor right
354 braces in the field will be treated specially (except as part of
355 variable substitution; see below).
357 COMMAND SUBSTITUTION WITH BRACKETS
358 ----------------------------------
359 If an open bracket occurs in a field of a command, then command
360 substitution occurs (except for fields enclosed in braces). All of the
361 text up to the matching close bracket is treated as a Tcl command and
362 executed immediately. Then the result of that command is substituted
363 for the bracketed text. For example, consider the command
367 When the `set` command has only a single argument, it is the name of a
368 variable and `set` returns the contents of that variable. In this case,
369 if variable 'b' has the value 'foo', then the command above is equivalent
374 Brackets can be used in more complex ways. For example, if the variable
375 'b' has the value 'foo' and the variable 'c' has the value 'gorp',
378 set a xyz[set b].[set c]
380 is equivalent to the command
385 A bracketed command may contain multiple commands separated by newlines
386 or semi-colons in the usual fashion. In this case the value of the last
387 command is used for substitution. For example, the command
392 is equivalent to the command
397 If a field is enclosed in braces then the brackets and the characters
398 between them are not interpreted specially; they are passed through to
399 the argument verbatim.
401 VARIABLE SUBSTITUTION WITH $
402 ----------------------------
403 The dollar sign (+$+) may be used as a special shorthand form for
404 substituting variable values. If +$+ appears in an argument that isn't
405 enclosed in braces then variable substitution will occur. The characters
406 after the +$+, up to the first character that isn't a number, letter,
407 or underscore, are taken as a variable name and the string value of that
408 variable is substituted for the name.
410 For example, if variable 'foo' has the value 'test', then the command
414 is equivalent to the command
418 There are two special forms for variable substitution. If the next
419 character after the name of the variable is an open parenthesis, then
420 the variable is assumed to be an array name, and all of the characters
421 between the open parenthesis and the next close parenthesis are taken as
422 an index into the array. Command substitutions and variable substitutions
423 are performed on the information between the parentheses before it is
426 For example, if the variable 'x' is an array with one element named
427 'first' and value '87' and another element named '14' and value 'more',
430 set a xyz$x(first)zyx
432 is equivalent to the command
436 If the variable 'index' has the value '14', then the command
438 set a xyz$x($index)zyx
440 is equivalent to the command
444 For more information on arrays, see VARIABLES AND ARRAYS below.
446 The second special form for variables occurs when the dollar sign is
447 followed by an open curly brace. In this case the variable name consists
448 of all the characters up to the next curly brace.
450 Array references are not possible in this form: the name between braces
451 is assumed to refer to a scalar variable. For example, if variable
452 'foo' has the value 'test', then the command
456 is equivalent to the command
461 Variable substitution does not occur in arguments that are enclosed in
462 braces: the dollar sign and variable name are passed through to the
465 The dollar sign abbreviation is simply a shorthand form. +$a+ is
466 completely equivalent to +[set a]+; it is provided as a convenience
469 SEPARATING COMMANDS WITH SEMI-COLONS
470 ------------------------------------
471 Normally, each command occupies one line (the command is terminated by a
472 newline character). However, semi-colon (+;+) is treated as a command
473 separator character; multiple commands may be placed on one line by
474 separating them with a semi-colon. Semi-colons are not treated as
475 command separators if they appear within curly braces or double-quotes.
477 BACKSLASH SUBSTITUTION
478 ----------------------
479 Backslashes may be used to insert non-printing characters into command
480 fields and also to insert special characters like braces and brackets
481 into fields without them being interpreted specially as described above.
483 The backslash sequences understood by the Tcl interpreter are
484 listed below. In each case, the backslash
485 sequence is replaced by the given character:
486 [[BackslashSequences]]
497 Carriage-return (0xd).
520 +{backslash}<space>+::
521 Space ( ): doesn't terminate argument.
524 Semi-colon: doesn't terminate command.
529 +{backslash}<newline>+::
530 Nothing: this joins two lines together
531 into a single line. This backslash feature is unique in that
532 it will be applied even when the sequence occurs within braces.
534 +{backslash}{backslash}+::
535 Backslash ('{backslash}').
538 The digits +'ddd'+ (one, two, or three of them) give the octal value of
539 the character. Note that Jim supports null characters in strings.
541 +{backslash}'unnnn'+::
542 The hex digits +'nnnn'+ (between one and four of them) give a unicode codepoint.
543 The UTF-8 encoding of the codepoint is inserted.
545 For example, in the command
549 the second argument to `set` will be +{x[ yza+.
551 If a backslash is followed by something other than one of the options
552 described above, then the backslash is transmitted to the argument
553 field without any special processing, and the Tcl scanner continues
554 normal processing with the next character. For example, in the
559 The first argument to `set` will be +{backslash}*a+ and the second
560 argument will be +{backslash}{foo+.
562 If an argument is enclosed in braces, then backslash sequences inside
563 the argument are parsed but no substitution occurs (except for
564 backslash-newline): the backslash
565 sequence is passed through to the argument as is, without making
566 any special interpretation of the characters in the backslash sequence.
567 In particular, backslashed braces are not counted in locating the
568 matching right brace that terminates the argument.
574 the second argument to `set` will be +{backslash}{abc+.
576 This backslash mechanism is not sufficient to generate absolutely
577 any argument structure; it only covers the
578 most common cases. To produce particularly complicated arguments
579 it is probably easiest to use the `format` command along with
580 command substitution.
582 STRING AND LIST INDEX SPECIFICATIONS
583 ------------------------------------
585 Many string and list commands take one or more 'index' parameters which
586 specify a position in the string relative to the start or end of the string/list.
588 The index may be one of the following forms:
591 A simple integer, where '0' refers to the first element of the string
594 +integer+integer+ or::
596 The sum or difference of the two integers. e.g. +2+3+ refers to the 5th element.
597 This is useful when used with (e.g.) +$i+1+ rather than the more verbose
601 The last element of the string or list.
604 The 'nth-from-last' element of the string or list.
608 1. A command is just a string.
609 2. Within a string commands are separated by newlines or semi-colons
610 (unless the newline or semi-colon is within braces or brackets
612 3. A command consists of fields. The first field is the name of the command.
613 The other fields are strings that are passed to that command as arguments.
614 4. Fields are normally separated by white space.
615 5. Double-quotes allow white space and semi-colons to appear within
617 Command substitution, variable substitution, and backslash substitution
618 still occur inside quotes.
619 6. Braces defer interpretation of special characters.
620 If a field begins with a left brace, then it consists of everything
621 between the left brace and the matching right brace. The
622 braces themselves are not included in the argument.
623 No further processing is done on the information between the braces
624 except that backslash-newline sequences are eliminated.
625 7. If a field doesn't begin with a brace then backslash,
626 variable, and command substitution are done on the field. Only a
627 single level of processing is done: the results of one substitution
628 are not scanned again for further substitutions or any other
629 special treatment. Substitution can
630 occur on any field of a command, including the command name
631 as well as the arguments.
632 8. If the first non-blank character of a command is a +\#+, everything
633 from the +#+ up through the next newline is treated as a comment
638 The second major interpretation applied to strings in Tcl is
639 as expressions. Several commands, such as `expr`, `for`,
640 and `if`, treat one or more of their arguments as expressions
641 and call the Tcl expression processors ('Jim_ExprLong',
642 'Jim_ExprBoolean', etc.) to evaluate them.
644 The operators permitted in Tcl expressions are a subset of
645 the operators permitted in C expressions, and they have the
646 same meaning and precedence as the corresponding C operators.
647 Expressions almost always yield numeric results
648 (integer or floating-point values).
649 For example, the expression
655 Tcl expressions differ from C expressions in the way that
656 operands are specified, and in that Tcl expressions support
657 non-numeric operands and string comparisons.
659 A Tcl expression consists of a combination of operands, operators,
662 White space may be used between the operands and operators and
663 parentheses; it is ignored by the expression processor.
664 Where possible, operands are interpreted as integer values.
666 Integer values may be specified in decimal (the normal case), in octal (if the
667 first character of the operand is '0'), or in hexadecimal (if the first
668 two characters of the operand are '0x').
670 If an operand does not have one of the integer formats given
671 above, then it is treated as a floating-point number if that is
672 possible. Floating-point numbers may be specified in any of the
673 ways accepted by an ANSI-compliant C compiler (except that the
674 'f', 'F', 'l', and 'L' suffixes will not be permitted in
675 most installations). For example, all of the
676 following are valid floating-point numbers: 2.1, 3., 6e4, 7.91e+16.
678 If no numeric interpretation is possible, then an operand is left
679 as a string (and only a limited set of operators may be applied to
682 1. Operands may be specified in any of the following ways:
684 2. As a numeric value, either integer or floating-point.
686 3. As a Tcl variable, using standard '$' notation.
687 The variable's value will be used as the operand.
689 4. As a string enclosed in double-quotes.
690 The expression parser will perform backslash, variable, and
691 command substitutions on the information between the quotes,
692 and use the resulting value as the operand
694 5. As a string enclosed in braces.
695 The characters between the open brace and matching close brace
696 will be used as the operand without any substitutions.
698 6. As a Tcl command enclosed in brackets.
699 The command will be executed and its result will be used as
702 Where substitutions occur above (e.g. inside quoted strings), they
703 are performed by the expression processor.
704 However, an additional layer of substitution may already have
705 been performed by the command parser before the expression
706 processor was called.
708 As discussed below, it is usually best to enclose expressions
709 in braces to prevent the command parser from performing substitutions
712 For some examples of simple expressions, suppose the variable 'a' has
713 the value 3 and the variable 'b' has the value 6. Then the expression
714 on the left side of each of the lines below will evaluate to the value
715 on the right side of the line:
720 {word one} < "word $a" 0
722 The valid operators are listed below, grouped in decreasing order
724 [[OperatorPrecedence]]
725 +int() double() round() abs(), rand(), srand()+::
726 Unary functions (except rand() which takes no arguments)
727 * +'int()'+ converts the numeric argument to an integer by truncating down.
728 * +'double()'+ converts the numeric argument to floating point.
729 * +'round()'+ converts the numeric argument to the closest integer value.
730 * +'abs()'+ takes the absolute value of the numeric argument.
731 * +'rand()'+ takes the absolute value of the numeric argument.
732 * +'rand()'+ returns a pseudo-random floating-point value in the range (0,1).
733 * +'srand()'+ takes an integer argument to (re)seed the random number generator. Returns the first random number from that seed.
735 +sin() cos() tan() asin() acos() atan() sinh() cosh() tanh() ceil() floor() exp() log() log10() sqrt()+::
736 Unary math functions.
737 If Jim is compiled with math support, these functions are available.
740 Unary minus, unary plus, bit-wise NOT, logical NOT. None of these operands
741 may be applied to string operands, and bit-wise NOT may be
742 applied only to integers.
745 Power. e.g. 'x^y^'. If Jim is compiled with math support, supports doubles and
746 integers. Otherwise supports integers only. (Note that the math-function form
747 has the same highest precedence)
750 Multiply, divide, remainder. None of these operands may be
751 applied to string operands, and remainder may be applied only
755 Add and subtract. Valid for any numeric operands.
758 Left and right shift, left and right rotate. Valid for integer operands only.
761 Boolean less, greater, less than or equal, and greater than or equal.
762 Each operator produces 1 if the condition is true, 0 otherwise.
763 These operators may be applied to strings as well as numeric operands,
764 in which case string comparison is used.
767 Boolean equal and not equal. Each operator produces a zero/one result.
768 Valid for all operand types. *Note* that values will be converted to integers
769 if possible, then floating point types, and finally strings will be compared.
770 It is recommended that 'eq' and 'ne' should be used for string comparison.
773 String equal and not equal. Uses the string value directly without
774 attempting to convert to a number first.
777 String in list and not in list. For 'in', result is 1 if the left operand (as a string)
778 is contained in the right operand (as a list), or 0 otherwise. The result for
779 +{$a ni $list}+ is equivalent to +{!($a in $list)}+.
782 Bit-wise AND. Valid for integer operands only.
785 Bit-wise OR. Valid for integer operands only.
788 Bit-wise exclusive OR. Valid for integer operands only.
791 Logical AND. Produces a 1 result if both operands are non-zero, 0 otherwise.
792 Valid for numeric operands only (integers or floating-point).
795 Logical OR. Produces a 0 result if both operands are zero, 1 otherwise.
796 Valid for numeric operands only (integers or floating-point).
799 If-then-else, as in C. If +'x'+
800 evaluates to non-zero, then the result is the value of +'y'+.
801 Otherwise the result is the value of +'z'+.
802 The +'x'+ operand must have a numeric value, while +'y'+ and +'z'+ can
805 See the C manual for more details on the results
806 produced by each operator.
807 All of the binary operators group left-to-right within the same
808 precedence level. For example, the expression
814 The +&&+, +||+, and +?:+ operators have 'lazy evaluation', just as
815 in C, which means that operands are not evaluated if they are not
816 needed to determine the outcome. For example, in
820 only one of +[a]+ or +[b]+ will actually be evaluated,
821 depending on the value of +$v+.
823 All internal computations involving integers are done with the C
824 type 'long long' if available, or 'long' otherwise, and all internal
825 computations involving floating-point are done with the C type
828 When converting a string to floating-point, exponent overflow is
829 detected and results in a Tcl error.
830 For conversion to integer from string, detection of overflow depends
831 on the behaviour of some routines in the local C library, so it should
832 be regarded as unreliable.
833 In any case, overflow and underflow are generally not detected
834 reliably for intermediate results.
836 Conversion among internal representations for integer, floating-point,
837 and string operands is done automatically as needed.
838 For arithmetic computations, integers are used until some
839 floating-point number is introduced, after which floating-point is used.
844 yields the result 1, while
847 5 / ( [string length "abcd"] + 0.0 )
849 both yield the result 1.25.
851 String values may be used as operands of the comparison operators,
852 although the expression evaluator tries to do comparisons as integer
853 or floating-point when it can.
854 If one of the operands of a comparison is a string and the other
855 has a numeric value, the numeric operand is converted back to
856 a string using the C 'sprintf' format specifier
857 '%d' for integers and '%g' for floating-point values.
858 For example, the expressions
863 both evaluate to 1. The first comparison is done using integer
864 comparison, and the second is done using string comparison after
865 the second operand is converted to the string '18'.
867 In general it is safest to enclose an expression in braces when
868 entering it in a command: otherwise, if the expression contains
869 any white space then the Tcl interpreter will split it
870 among several arguments. For example, the command
874 results in three arguments being passed to `expr`: +$a+,
875 \+, and +$b+. In addition, if the expression isn't in braces
876 then the Tcl interpreter will perform variable and command substitution
877 immediately (it will happen in the command parser rather than in
878 the expression parser). In many cases the expression is being
879 passed to a command that will evaluate the expression later (or
880 even many times if, for example, the expression is to be used to
881 decide when to exit a loop). Usually the desired goal is to re-do
882 the variable or command substitutions each time the expression is
883 evaluated, rather than once and for all at the beginning. For example,
886 for {set i 1} $i<=10 {incr i} {...} ** WRONG **
888 is probably intended to iterate over all values of +i+ from 1 to 10.
889 After each iteration of the body of the loop, `for` will pass
890 its second argument to the expression evaluator to see whether or not
891 to continue processing. Unfortunately, in this case the value of +i+
892 in the second argument will be substituted once and for all when the
893 `for` command is parsed. If +i+ was 0 before the `for`
894 command was invoked then the second argument of `for` will be +0\<=10+
895 which will always evaluate to 1, even though +i+ eventually
896 becomes greater than 10. In the above case the loop will never
897 terminate. Instead, the expression should be placed in braces:
899 for {set i 1} {$i<=10} {incr i} {...} ** RIGHT **
901 This causes the substitution of 'i'
902 to be delayed; it will be re-done each time the expression is
903 evaluated, which is the desired result.
907 The third major way that strings are interpreted in Tcl is as lists.
908 A list is just a string with a list-like structure
909 consisting of fields separated by white space. For example, the
914 is a list with four elements or fields.
915 Lists have the same basic structure as command strings, except
916 that a newline character in a list is treated as a field separator
917 just like space or tab. Conventions for braces and quotes
918 and backslashes are the same for lists as for commands. For example,
923 is a list with three elements: +a+, +b c+, and +d e {f g h}+.
925 Whenever an element is extracted from a list, the same rules about
926 braces and quotes and backslashes are applied as for commands. Thus in
927 the example above when the third element is extracted from the list,
932 (when the field was extracted, all that happened was to strip off
933 the outermost layer of braces). Command substitution and
934 variable substitution are never
935 made on a list (at least, not by the list-processing commands; the
936 list can always be passed to the Tcl interpreter for evaluation).
938 The Tcl commands `concat`, `foreach`, `lappend`, `lindex`, `linsert`,
939 `list`, `llength`, `lrange`, `lreplace`, `lsearch`, and `lsort` allow
940 you to build lists, extract elements from them, search them, and perform
941 other list-related functions.
943 Advanced list commands include `lrepeat`, `lreverse`, `lmap`, `lassign`, `lset`.
948 A new addition to Tcl 8.5 is the ability to expand a list into separate
949 arguments. Support for this feature is also available in Jim.
951 Consider the following attempt to exec a list:
956 This will attempt to exec the a command named "ls -l", which will clearly not
957 work. Typically eval and concat are required to solve this problem, however
958 it can be solved much more easily with +\{*\}+.
962 This will expand the following argument into individual elements and then evaluate
963 the resulting command.
965 Note that the official Tcl syntax is +\{*\}+, however +\{expand\}+ is retained
966 for backward compatibility with experimental versions of this feature.
970 Tcl provides two commands that support string matching using regular
971 expressions, `regexp` and `regsub`, as well as `switch -regexp` and
974 Regular expressions may be implemented one of two ways. Either using the system's C library
975 POSIX regular expression support, or using the built-in regular expression engine.
976 The differences between these are described below.
978 *NOTE* Tcl 7.x and 8.x use perl-style Advanced Regular Expressions (+ARE+).
980 POSIX Regular Expressions
981 ~~~~~~~~~~~~~~~~~~~~~~~~~
982 If the system supports POSIX regular expressions, and UTF-8 support is not enabled,
983 this support will be used by default. The type of regular expressions supported are
984 Extended Regular Expressions (+ERE+) rather than Basic Regular Expressions (+BRE+).
985 See REG_EXTENDED in the documentation.
987 Using the system-supported POSIX regular expressions will typically
988 make for the smallest code size, but some features such as UTF-8
989 and +{backslash}w+, +{backslash}d+, +{backslash}s+ are not supported.
991 See regex(3) and regex(7) for full details.
993 Jim built-in Regular Expressions
994 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
995 The Jim built-in regulare expression engine may be selected with +./configure --with-jim-regexp+
996 or it will be selected automatically if UTF-8 support is enabled.
998 This engine supports UTF-8 as well as some +ARE+ features. The differences with both Tcl 7.x/8.x
999 and POSIX are highlighted below.
1001 1. UTF-8 strings and patterns are both supported
1002 2. Supported character classes: +[:alnum:]+, +[:digit:]+ and +[:space:]+
1003 3. Supported shorthand character classes: +{backslash}w+ = +[:alnum:]+, +{backslash}d+ = +[:digit:],+ +{backslash}s+ = +[:space:]+
1004 4. Character classes apply to ASCII characters only
1005 5. Supported constraint escapes: +{backslash}m+ = +{backslash}<+ = start of word, +{backslash}M+ = +{backslash}>+ = end of word
1006 6. Backslash escapes may be used within regular expressions, such as +{backslash}n+ = newline, +{backslash}uNNNN+ = unicode
1007 7. Support for the +?+ non-greedy quantifier. e.g. +*?+
1008 8. Support for non-capuring parentheses +(?:...)+
1012 Each command produces two results: a code and a string. The
1013 code indicates whether the command completed successfully or not,
1014 and the string gives additional information. The valid codes are
1015 defined in jim.h, and are:
1018 This is the normal return code, and indicates that the command completed
1019 successfully. The string gives the command's return value.
1022 Indicates that an error occurred; the string gives a message describing
1026 Indicates that the `return` command has been invoked, and that the
1027 current procedure (or top-level command or `source` command)
1028 should return immediately. The
1029 string gives the return value for the procedure or command.
1032 Indicates that the `break` command has been invoked, so the
1033 innermost loop should abort immediately. The string should always
1037 Indicates that the `continue` command has been invoked, so the
1038 innermost loop should go on to the next iteration. The string
1039 should always be empty.
1042 Indicates that a signal was caught while executing a commands.
1043 The string contains the name of the signal caught.
1044 See the `signal` and `catch` commands.
1047 Indicates that the command called the `exit` command.
1048 The string contains the exit code.
1050 Tcl programmers do not normally need to think about return codes,
1051 since +JIM_OK+ is almost always returned. If anything else is returned
1052 by a command, then the Tcl interpreter immediately stops processing
1053 commands and returns to its caller. If there are several nested
1054 invocations of the Tcl interpreter in progress, then each nested
1055 command will usually return the error to its caller, until eventually
1056 the error is reported to the top-level application code. The
1057 application will then display the error message for the user.
1059 In a few cases, some commands will handle certain `error` conditions
1060 themselves and not return them upwards. For example, the `for`
1061 command checks for the +JIM_BREAK+ code; if it occurs, then `for`
1062 stops executing the body of the loop and returns +JIM_OK+ to its
1063 caller. The `for` command also handles +JIM_CONTINUE+ codes and the
1064 procedure interpreter handles +JIM_RETURN+ codes. The `catch`
1065 command allows Tcl programs to catch errors and handle them without
1066 aborting command interpretation any further.
1068 The `info returncodes` command may be used to programmatically map between
1069 return codes and names.
1073 Tcl allows you to extend the command interface by defining
1074 procedures. A Tcl procedure can be invoked just like any other Tcl
1075 command (it has a name and it receives one or more arguments).
1076 The only difference is that its body isn't a piece of C code linked
1077 into the program; it is a string containing one or more other
1080 The `proc` command is used to create a new Tcl command procedure:
1082 +*proc* 'name arglist ?statics? body'+
1084 The new command is named +'name'+, and it replaces any existing command
1085 there may have been by that name. Whenever the new command is
1086 invoked, the contents of +'body'+ will be executed by the Tcl
1089 +'arglist'+ specifies the formal arguments to the procedure.
1090 It consists of a list, possibly empty, of the following
1091 argument specifiers:
1094 Required Argument - A simple argument name.
1097 Optional Argument - A two-element list consisting of the
1098 argument name, followed by the default value, which will
1099 be used if the corresponding argument is not supplied.
1102 Reference Argument - The caller is expected to pass the name of
1103 an existing variable. An implicit `upvar 1 'origname' 'name'` is done
1104 to make the variable available in the proc scope.
1107 Variable Argument - The special name +'args'+, which is
1108 assigned all remaining arguments (including none) as a list. The
1109 variable argument may only be specified once. Note that
1110 the syntax +args newname+ may be used to retain the special
1111 behaviour of +'args'+ with a different local name. In this case,
1112 the variable is named +'newname'+ rather than +'args'+.
1114 When the command is invoked, a local variable will be created for each of
1115 the formal arguments to the procedure; its value will be the value
1116 of corresponding argument in the invoking command or the argument's
1119 Arguments with default values need not be specified in a procedure
1120 invocation. However, there must be enough actual arguments for all
1121 required arguments, and there must not be any extra actual arguments
1122 (unless the Variable Argument is specified).
1124 Actual arguments are assigned to formal arguments as in left-to-right
1125 order with the following precedence.
1127 1. Required Arguments (including Reference Arguments)
1128 2. Optional Arguments
1129 3. Variable Argument
1131 The following example illustrates precedence. Assume a procedure declaration:
1133 proc p {{a A} args b {c C} d} {...}
1135 This procedure requires at least two arguments, but can accept an unlimited number.
1136 The following table shows how various numbers of arguments are assigned.
1137 Values marked as +-+ are assigned the default value.
1139 [width="40%",frame="topbot",options="header"]
1141 |Number of arguments|a|args|b|c|d
1149 When +'body'+ is being executed, variable names normally refer to local
1150 variables, which are created automatically when referenced and deleted
1151 when the procedure returns. One local variable is automatically created
1152 for each of the procedure's arguments. Global variables can be
1153 accessed by invoking the `global` command or via the +::+ prefix.
1157 In addition to procedure arguments, Jim procedures may declare static variables.
1158 These variables scoped to the procedure and initialised at procedure definition.
1159 Either from the static variable definition, or from the enclosing scope.
1161 Consider the following example:
1164 jim> proc a {} {a {b 2}} {
1176 The static variable +'a'+ has no initialiser, so it is initialised from
1177 the enclosing scope with the value 1. (Note that it is an error if there
1178 is no variable with the same name in the enclosing scope). However +'b'+
1179 has an initialiser, so it is initialised to 2.
1181 Unlike a local variable, the value of a static variable is retained across
1182 invocations of the procedure.
1184 See the `proc` command for information on
1185 how to define procedures and what happens when they are invoked.
1187 VARIABLES - SCALARS AND ARRAYS
1188 ------------------------------
1189 Tcl allows the definition of variables and the use of their values
1190 either through '$'-style variable substitution, the `set`
1191 command, or a few other mechanisms.
1193 Variables need not be declared: a new variable will automatically
1194 be created each time a new variable name is used.
1196 Tcl supports two types of variables: scalars and arrays.
1197 A scalar variable has a single value, whereas an array variable
1198 can have any number of elements, each with a name (called
1199 its 'index') and a value.
1201 Array indexes may be arbitrary strings; they need not be numeric.
1202 Parentheses are used refer to array elements in Tcl commands.
1203 For example, the command
1207 will modify the element of 'x' whose index is 'first'
1208 so that its new value is '44'.
1210 Two-dimensional arrays can be simulated in Tcl by using indexes
1211 that contain multiple concatenated values.
1212 For example, the commands
1217 set the elements of 'a' whose indexes are '2,3' and '3,6'.
1219 In general, array elements may be used anywhere in Tcl that scalar
1220 variables may be used.
1222 If an array is defined with a particular name, then there may
1223 not be a scalar variable with the same name.
1225 Similarly, if there is a scalar variable with a particular
1226 name then it is not possible to make array references to the
1229 To convert a scalar variable to an array or vice versa, remove
1230 the existing variable with the `unset` command.
1232 The `array` command provides several features for dealing
1233 with arrays, such as querying the names of all the elements of
1234 the array and converting between an array and a list.
1236 Variables may be either global or local. If a variable
1237 name is used when a procedure isn't being executed, then it
1238 automatically refers to a global variable. Variable names used
1239 within a procedure normally refer to local variables associated with that
1240 invocation of the procedure. Local variables are deleted whenever
1241 a procedure exits. Either `global` command may be used to request
1242 that a name refer to a global variable for the duration of the current
1243 procedure (this is somewhat analogous to 'extern' in C), or the variable
1244 may be explicitly scoped with the +::+ prefix. For example
1260 ARRAYS AS LISTS IN JIM
1261 ----------------------
1262 Unlike Tcl, Jim can automatically convert between a list (with an even
1263 number of elements) and an array value. This is similar to the way Tcl
1264 can convert between a string and a list.
1275 Thus `array set` is equivalent to `set` when the variable does not
1278 The reverse is also true where an array will be converted into
1281 set a(1) one; set a(2) two
1290 Tcl 8.5 introduced the dict command, and Jim Tcl has added a version
1291 of this command. Dictionaries provide efficient access to key-value
1292 pairs, just like arrays, but dictionaries are pure values. This
1293 means that you can pass them to a procedure just as a list or a
1294 string. Tcl dictionaries are therefore much more like Tcl lists,
1295 except that they represent a mapping from keys to values, rather
1296 than an ordered sequence.
1298 You can nest dictionaries, so that the value for a particular key
1299 consists of another dictionary. That way you can elegantly build
1300 complicated data structures, such as hierarchical databases. You
1301 can also combine dictionaries with other Tcl data structures. For
1302 instance, you can build a list of dictionaries that themselves
1305 Dictionaries are values that contain an efficient, order-preserving
1306 mapping from arbitrary keys to arbitrary values. Each key in the
1307 dictionary maps to a single value. They have a textual format that
1308 is exactly that of any list with an even number of elements, with
1309 each mapping in the dictionary being represented as two items in
1310 the list. When a command takes a dictionary and produces a new
1311 dictionary based on it (either returning it or writing it back into
1312 the variable that the starting dictionary was read from) the new
1313 dictionary will have the same order of keys, modulo any deleted
1314 keys and with new keys added on to the end. When a string is
1315 interpreted as a dictionary and it would otherwise have duplicate
1316 keys, only the last value for a particular key is used; the others
1317 are ignored, meaning that, "apple banana" and "apple carrot apple
1318 banana" are equivalent dictionaries (with different string
1321 Note that in Jim, arrays are implemented as dictionaries.
1322 Thus automatic conversion between lists and dictionaries applies
1323 as it does for arrays.
1325 jim> dict set a 1 one
1327 jim> dict set a 2 two
1333 jim> dict set a 3 T three
1334 1 one 2 two 3 {T three}
1336 See the `dict` command for more details.
1338 GARBAGE COLLECTION, REFERENCES, LAMBDA
1339 --------------------------------------
1340 Unlike Tcl, Jim has some sophisticated support for functional programming.
1341 These are described briefly below.
1343 More information may be found at http://wiki.tcl.tk/13847
1347 A reference can be thought of as holding a value with one level of indirection,
1348 where the value may be garbage collected when unreferenced.
1349 Consider the following example:
1351 jim> set r [ref "One String" test]
1352 <reference.<test___>.00000000000000000000>
1356 The operation `ref` creates a references to the value specified by the
1357 first argument. (The second argument is a "type" used for documentation purposes).
1359 The operation `getref` is the dereferencing operation which retrieves the value
1360 stored in the reference.
1362 jim> setref $r "New String"
1367 The operation `setref` replaces the value stored by the reference. If the old value
1368 is no longer accessible by any reference, it will eventually be automatically be garbage
1373 Normally, all values in Tcl are passed by value. As such values are copied and released
1374 automatically as necessary.
1376 With the introduction of references, it is possible to create values whose lifetime
1377 transcend their scope. To support this, case, the Jim system will periodically identify
1378 and discard objects which are no longer accessible by any reference.
1380 The `collect` command may be used to force garbage collection. Consider a reference created
1383 jim> proc f {ref value} { puts "Finaliser called for $ref,$value" }
1384 jim> set r [ref "One String" test f]
1385 <reference.<test___>.00000000000
1390 Finaliser called for <reference.<test___>.00000000000,One String
1393 Note that once the reference, 'r', was modified so that it no longer
1394 contained a reference to the value, the garbage collector discarded
1395 the value (after calling the finalizer).
1397 The finalizer for a reference may be examined or changed with the `finalize` command
1401 jim> finalize $r newf
1406 Jim provides a garbage collected lambda function. This is a procedure
1407 which is able to create an anonymous procedure. Consider:
1409 jim> set f [lambda {a} {{x 0}} { incr x $a }]
1416 This create an anonymous procedure (with the name stored in 'f'), with a static variable
1417 which is incremented by the supplied value and the result returned.
1419 Once the procedure name is no longer accessible, it will automatically be deleted
1420 when the garbage collector runs.
1422 The procedure may also be delete immediately by renaming it "". e.g.
1428 If Jim is built with UTF-8 support enabled (configure --enable-utf),
1429 then most string-related commands become UTF-8 aware. These include,
1430 but are not limited to, `string match`, `split`, `glob`, `scan` and
1433 UTF-8 encoding has many advantages, but one of the complications is that
1434 characters can take a variable number of bytes. Thus the addition of
1435 `string bytelength` which returns the number of bytes in a string,
1436 while `string length` returns the number of characters.
1438 If UTF-8 support is not enabled, all commands treat bytes as characters
1439 and `string bytelength` returns the same value as `string length`.
1441 Note that even if UTF-8 support is not enabled, the +{backslash}uNNNN+ syntax
1442 is still available to embed UTF-8 sequences.
1446 Commands such as `string match`, `lsearch -glob`, `array names` and others use string
1447 pattern matching rules. These commands support UTF-8. For example:
1449 string match a\[\ua0-\ubf\]b "a\u00a3b"
1453 +format %c+ allows a unicode codepoint to be be encoded. For example, the following will return
1454 a string with two bytes and one character. The same as +{backslash}ub5+
1458 `format` respects widths as character widths, not byte widths. For example, the following will
1459 return a string with three characters, not three bytes.
1461 format %.3s \ub5\ub6\ub7\ub8
1463 Similarly, +scan ... %c+ allows a UTF-8 to be decoded to a unicode codepoint. The following will set
1464 +'a'+ to 181 (0xb5) and +'b'+ to 65 (0x41).
1466 scan \u00b5A %c%c a b
1468 `scan %s` will also accept a character class, including unicode ranges.
1472 `string is` has *not* been extended to classify UTF-8 characters. Therefore, the following
1473 will return 0, even though the string may be considered to be alphabetic.
1475 string is alpha \ub5Test
1477 This does not affect the string classes 'ascii', 'control', 'digit', 'double', 'integer' or 'xdigit'.
1479 Case Mapping and Conversion
1480 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
1481 Jim provides a simplified unicode case mapping. This means that case conversion
1482 and comparison will not increase or decrease the number of characters in a string.
1484 `string toupper` will convert any lowercase letters to their uppercase equivalent.
1485 Any character which is not a letter or has no uppercase equivalent is left unchanged.
1486 Similarly for `string tolower`.
1488 Commands which perform case insensitive matches, such as `string compare -nocase`
1489 and `lsearch -nocase` fold both strings to uppercase before comparison.
1491 Invalid UTF-8 Sequences
1492 ~~~~~~~~~~~~~~~~~~~~~~~
1493 Some UTF-8 character sequences are invalid, such as those beginning with '0xff',
1494 those which represent character sequences longer than 3 bytes (greater than U+FFFF),
1495 and those which end prematurely, such as a lone '0xc2'.
1497 In these situations, the offending bytes are treated as single characters. For example,
1498 the following returns 2.
1500 string bytelength \xff\xff
1504 If UTF-8 support is enabled, the built-in regular expression engine will be
1505 selected which supports UTF-8 strings and patterns.
1507 See REGULAR EXPRESSIONS
1511 The Tcl library provides the following built-in commands, which will
1512 be available in any application using Tcl. In addition to these
1513 built-in commands, there may be additional commands defined by each
1514 application, plus commands defined as Tcl procedures.
1516 In the command syntax descriptions below, words in +*boldface*+ are
1517 literals that you type verbatim to Tcl.
1519 Words in +'italics'+ are meta-symbols; they serve as names for any of
1520 a range of values that you can type.
1522 Optional arguments or groups of arguments are indicated by enclosing them
1523 in +?question-marks?+.
1525 Ellipses (+\...+) indicate that any number of additional
1526 arguments or groups of arguments may appear, in the same format
1527 as the preceding argument(s).
1538 Delivers the +SIGALRM+ signal to the process after the given
1539 number of seconds. If the platform supports 'ualarm(3)' then
1540 the argument may be a floating point value. Otherwise it must
1543 Note that unless a signal handler for +SIGALRM+ has been installed
1544 (see `signal`), the process will exit on this signal.
1548 +*alias* 'name args\...'+
1550 Creates a single word alias (command) for one or more words. For example,
1551 the following creates an alias for the command `info exists`.
1558 `alias` returns +'name'+, allowing it to be used with `local`.
1560 See also `proc`, `curry`, `lambda`, `local`, `info alias`
1564 +*append* 'varName value ?value value ...?'+
1566 Append all of the +'value'+ arguments to the current value
1567 of variable +'varName'+. If +'varName'+ doesn't exist,
1568 it is given a value equal to the concatenation of all the
1569 +'value'+ arguments.
1571 This command provides an efficient way to build up long
1572 variables incrementally.
1573 For example, "`append a $b`" is much more efficient than
1574 "`set a $a$b`" if +$a+ is long.
1578 +*array* 'option arrayName ?arg\...?'+
1580 This command performs one of several operations on the
1581 variable given by +'arrayName'+.
1583 Note that in general, if the named array does not exist, the +'array'+ command behaves
1584 as though the array exists but is empty.
1586 The +'option'+ argument determines what action is carried out by the
1587 command. The legal +'options'+ (which may be abbreviated) are:
1589 +*array exists* 'arrayName'+::
1590 Returns 1 if arrayName is an array variable, 0 if there is
1591 no variable by that name. This command is essentially
1592 identical to `info exists`
1594 +*array get* 'arrayName ?pattern?'+::
1595 Returns a list containing pairs of elements. The first
1596 element in each pair is the name of an element in arrayName
1597 and the second element of each pair is the value of the
1598 array element. The order of the pairs is undefined. If
1599 pattern is not specified, then all of the elements of the
1600 array are included in the result. If pattern is specified,
1601 then only those elements whose names match pattern (using
1602 the matching rules of string match) are included. If arrayName
1603 isn't the name of an array variable, or if the array contains
1604 no elements, then an empty list is returned.
1606 +*array names* 'arrayName ?pattern?'+::
1607 Returns a list containing the names of all of the elements
1608 in the array that match pattern. If pattern is omitted then
1609 the command returns all of the element names in the array.
1610 If pattern is specified, then only those elements whose
1611 names match pattern (using the matching rules of string
1612 match) are included. If there are no (matching) elements
1613 in the array, or if arrayName isn't the name of an array
1614 variable, then an empty string is returned.
1616 +*array set* 'arrayName list'+::
1617 Sets the values of one or more elements in arrayName. list
1618 must have a form like that returned by array get, consisting
1619 of an even number of elements. Each odd-numbered element
1620 in list is treated as an element name within arrayName, and
1621 the following element in list is used as a new value for
1622 that array element. If the variable arrayName does not
1623 already exist and list is empty, arrayName is created with
1624 an empty array value.
1626 +*array size* 'arrayName'+::
1627 Returns the number of elements in the array. If arrayName
1628 isn't the name of an array then 0 is returned.
1630 +*array unset* 'arrayName ?pattern?'+::
1631 Unsets all of the elements in the array that match pattern
1632 (using the matching rules of string match). If arrayName
1633 isn't the name of an array variable or there are no matching
1634 elements in the array, no error will be raised. If pattern
1635 is omitted and arrayName is an array variable, then the
1636 command unsets the entire array. The command always returns
1643 This command may be invoked only inside the body of a loop command
1644 such as `for` or `foreach` or `while`. It returns a +JIM_BREAK+ code
1645 to signal the innermost containing loop command to return immediately.
1649 +*case* 'string' ?in? 'patList body ?patList body ...?'+
1651 +*case* 'string' ?in? {'patList body ?patList body ...?'}+
1653 *Note* that the `switch` command should generally be preferred unless compatibility
1654 with Tcl 6.x is desired.
1656 Match +'string'+ against each of the +'patList'+ arguments
1657 in order. If one matches, then evaluate the following +'body'+ argument
1658 by passing it recursively to the Tcl interpreter, and return the result
1659 of that evaluation. Each +'patList'+ argument consists of a single
1660 pattern or list of patterns. Each pattern may contain any of the wild-cards
1661 described under `string match`.
1663 If a +'patList'+ argument is +default+, the corresponding body will be
1664 evaluated if no +'patList'+ matches +'string'+. If no +'patList'+ argument
1665 matches +'string'+ and no default is given, then the `case` command returns
1668 Two syntaxes are provided.
1670 The first uses a separate argument for each of the patterns and commands;
1671 this form is convenient if substitutions are desired on some of the
1672 patterns or commands.
1674 The second form places all of the patterns and commands together into
1675 a single argument; the argument must have proper list structure, with
1676 the elements of the list being the patterns and commands.
1678 The second form makes it easy to construct multi-line case commands,
1679 since the braces around the whole list make it unnecessary to include a
1680 backslash at the end of each line.
1682 Since the +'patList'+ arguments are in braces in the second form,
1683 no command or variable substitutions are performed on them; this makes
1684 the behaviour of the second form different than the first form in some
1687 Below are some examples of `case` commands:
1689 case abc in {a b} {format 1} default {format 2} a* {format 3}
1699 will return '1', and
1714 +*catch* ?-?no?'code \...'? ?--? 'command ?resultVarName? ?optionsVarName?'+
1716 The `catch` command may be used to prevent errors from aborting
1717 command interpretation. `catch` evaluates +'command'+, and returns a
1718 +JIM_OK+ code, regardless of any errors that might occur while
1719 executing +'command'+ (with the possible exception of +JIM_SIGNAL+ -
1722 The return value from `catch` is a decimal string giving the code
1723 returned by the Tcl interpreter after executing +'command'+. This
1724 will be '0' (+JIM_OK+) if there were no errors in +'command'+; otherwise
1725 it will have a non-zero value corresponding to one of the exceptional
1726 return codes (see jim.h for the definitions of code values, or the
1727 `info returncodes` command).
1729 If the +'resultVarName'+ argument is given, then it gives the name
1730 of a variable; `catch` will set the value of the variable to the
1731 string returned from +'command'+ (either a result or an error message).
1733 If the +'optionsVarName'+ argument is given, then it gives the name
1734 of a variable; `catch` will set the value of the variable to a
1735 dictionary. For any return code other than +JIM_RETURN+, the value
1736 for the key +-code+ will be set to the return code. For +JIM_RETURN+
1737 it will be set to the code given in `return -code`. Additionally,
1738 for the return code +JIM_ERR+, the value of the key +-errorinfo+
1739 will contain the current stack trace (the same result as `info stacktrace`),
1740 the value of the key +-errorcode+ will contain the
1741 same value as the global variable $::errorCode, and the value of
1742 the key +-level+ will be the current return level (see `return -level`).
1743 This can be useful to rethrow an error:
1745 if {[catch {...} msg opts]} {
1746 ...maybe do something with the error...
1748 return {*}$opts $msg
1751 Normally `catch` will +'not'+ catch any of the codes +JIM_EXIT+, +JIM_EVAL+ or +JIM_SIGNAL+.
1752 The set of codes which will be caught may be modified by specifying the one more codes before
1755 e.g. To catch +JIM_EXIT+ but not +JIM_BREAK+ or +JIM_CONTINUE+
1757 catch -exit -nobreak -nocontinue -- { ... }
1759 The use of +--+ is optional. It signifies that no more return code options follow.
1761 Note that if a signal marked as `signal handle` is caught with `catch -signal`, the return value
1762 (stored in +'resultVarName'+) is name of the signal caught.
1768 Change the current working directory to +'dirName'+.
1770 Returns an empty string.
1772 This command can potentially be disruptive to an application, so it may
1773 be removed in some applications.
1778 Returns the current time as seconds since the epoch.
1780 +*clock format* 'seconds' ?*-format* 'format?'+::
1781 Format the given time (seconds since the epoch) according to the given
1782 format. See strftime(3) for supported formats.
1783 If no format is supplied, "%c" is used.
1785 +*clock scan* 'str' *-format* 'format'+::
1786 Scan the given time string using the given format string.
1787 See strptime(3) for supported formats.
1795 Closes the file given by +'fileId'+.
1796 +'fileId'+ must be the return value from a previous invocation
1797 of the `open` command; after this command, it should not be
1804 Normally reference garbage collection is automatically performed periodically.
1805 However it may be run immediately with the `collect` command.
1807 See GARBAGE COLLECTION, REFERENCES, LAMBDA for more detail.
1811 +*concat* 'arg ?arg \...?'+
1813 This command treats each argument as a list and concatenates them
1814 into a single list. It permits any number of arguments. For example,
1817 concat a b {c d e} {f {g h}}
1829 This command may be invoked only inside the body of a loop command such
1830 as `for` or `foreach` or `while`. It returns a +JIM_CONTINUE+ code to
1831 signal the innermost containing loop command to skip the remainder of
1832 the loop's body but continue with the next iteration of the loop.
1836 +*alias* 'args\...'+
1838 Similar to `alias` except it creates an anonymous procedure (lambda) instead of
1841 the following creates a local, unnamed alias for the command `info exists`.
1843 set e [local curry info exists]
1848 `curry` returns the name of the procedure.
1850 See also `proc`, `alias`, `lambda`, `local`.
1854 +*dict* 'option ?arg\...?'+
1856 Performs one of several operations on dictionary values.
1858 The +'option'+ argument determines what action is carried out by the
1859 command. The legal +'options'+ are:
1861 +*dict create* '?key value \...?'+::
1862 Create and return a new dictionary value that contains each of
1863 the key/value mappings listed as arguments (keys and values
1864 alternating, with each key being followed by its associated
1867 +*dict exists* 'dictionary key ?key \...?'+::
1868 Returns a boolean value indicating whether the given key (or path
1869 of keys through a set of nested dictionaries) exists in the given
1870 dictionary value. This returns a true value exactly when `dict get`
1871 on that path will succeed.
1873 +*dict get* 'dictionary ?key \...?'+::
1874 Given a dictionary value (first argument) and a key (second argument),
1875 this will retrieve the value for that key. Where several keys are
1876 supplied, the behaviour of the command shall be as if the result
1877 of "`dict get $dictVal $key`" was passed as the first argument to
1878 dict get with the remaining arguments as second (and possibly
1879 subsequent) arguments. This facilitates lookups in nested dictionaries.
1880 If no keys are provided, dict would return a list containing pairs
1881 of elements in a man- ner similar to array get. That is, the first
1882 element of each pair would be the key and the second element would
1883 be the value for that key. It is an error to attempt to retrieve
1884 a value for a key that is not present in the dictionary.
1886 +*dict keys* 'dictionary ?pattern?'+::
1887 Returns a list of the keys in the dictionary.
1888 If pattern is specified, then only those keys whose
1889 names match +'pattern'+ (using the matching rules of string
1890 match) are included.
1892 +*dict merge* ?'dictionary \...'?+::
1893 Return a dictionary that contains the contents of each of the
1894 +'dictionary'+ arguments. Where two (or more) dictionaries
1895 contain a mapping for the same key, the resulting dictionary
1896 maps that key to the value according to the last dictionary on
1897 the command line containing a mapping for that key.
1899 +*dict set* 'dictionaryName key ?key \...? value'+::
1900 This operation takes the +'name'+ of a variable containing a dictionary
1901 value and places an updated dictionary value in that variable
1902 containing a mapping from the given key to the given value. When
1903 multiple keys are present, this operation creates or updates a chain
1904 of nested dictionaries.
1906 +*dict size* 'dictionary'+::
1907 Return the number of key/value mappings in the given dictionary value.
1909 +*dict unset* 'dictionaryName key ?key \...? value'+::
1910 This operation (the companion to `dict set`) takes the name of a
1911 variable containing a dictionary value and places an updated
1912 dictionary value in that variable that does not contain a mapping
1913 for the given key. Where multiple keys are present, this describes
1914 a path through nested dictionaries to the mapping to remove. At
1915 least one key must be specified, but the last key on the key-path
1916 need not exist. All other components on the path must exist.
1918 +*dict with* 'dictionaryName key ?key \...? script'+::
1919 Execute the Tcl script in +'script'+ with the value for each
1920 key in +'dictionaryName'+ mapped to a variable with the same
1921 name. Where one or more keys are given, these indicate a chain
1922 of nested dictionaries, with the innermost dictionary being the
1923 one opened out for the execution of body. Making +'dictionaryName'+
1924 unreadable will make the updates to the dictionary be discarded,
1925 and this also happens if the contents of +'dictionaryName'+ are
1926 adjusted so that the chain of dictionaries no longer exists.
1927 The result of `dict with` is (unless some kind of error occurs)
1928 the result of the evaluation of body.
1930 The variables are mapped in the scope enclosing the `dict with`;
1931 it is recommended that this command only be used in a local
1932 scope (procedure). Because of this, the variables set by
1933 `dict with` will continue to exist after the command finishes (unless
1934 explicitly unset). Note that changes to the contents of +'dictionaryName'+
1935 only happen when +'script'+ terminates.
1939 +*env* '?name? ?default?'+
1941 If +'name'+ is supplied, returns the value of +'name'+ from the initial
1942 environment (see getenv(3)). An error is returned if +'name'+ does not
1943 exist in the environment, unless +'default'+ is supplied - in which case
1944 that value is returned instead.
1946 If no arguments are supplied, returns a list of all environment variables
1947 and their values as +{name value \...}+
1949 See also the global variable +::env+
1957 Returns 1 if an end-of-file condition has occurred on +'fileId'+,
1960 +'fileId'+ must have been the return value from a previous call to `open`,
1961 or it may be +stdin+, +stdout+, or +stderr+ to refer to one of the
1962 standard I/O channels.
1966 +*error* 'message ?stacktrace?'+
1968 Returns a +JIM_ERR+ code, which causes command interpretation to be
1969 unwound. +'message'+ is a string that is returned to the application
1970 to indicate what went wrong.
1972 If the +'stacktrace'+ argument is provided and is non-empty,
1973 it is used to initialize the stacktrace.
1975 This feature is most useful in conjunction with the `catch` command:
1976 if a caught error cannot be handled successfully, +'stacktrace'+ can be used
1977 to return a stack trace reflecting the original point of occurrence
1982 error $errMsg [info stacktrace]
1984 See also `errorInfo`, `info stacktrace`, `catch` and `return`
1988 +*errorInfo* 'error ?stacktrace?'+
1990 Returns a human-readable representation of the given error message and stack trace.
1993 if {[catch {...} error]} {
1994 puts stderr [errorInfo $error [info stacktrace]]
2002 +*eval* 'arg ?arg\...?'+
2004 `eval` takes one or more arguments, which together comprise a Tcl
2005 command (or collection of Tcl commands separated by newlines in the
2006 usual way). `eval` concatenates all its arguments in the same
2007 fashion as the `concat` command, passes the concatenated string to the
2008 Tcl interpreter recursively, and returns the result of that
2009 evaluation (or any error generated by it).
2013 +*exec* 'arg ?arg\...?'+
2015 This command treats its arguments as the specification
2016 of one or more UNIX commands to execute as subprocesses.
2017 The commands take the form of a standard shell pipeline;
2018 +|+ arguments separate commands in the
2019 pipeline and cause standard output of the preceding command
2020 to be piped into standard input of the next command (or +|&+ for
2021 both standard output and standard error).
2023 Under normal conditions the result of the `exec` command
2024 consists of the standard output produced by the last command
2027 If any of the commands in the pipeline exit abnormally or
2028 are killed or suspended, then `exec` will return an error
2029 and the error message will include the pipeline's output followed by
2030 error messages describing the abnormal terminations.
2032 If any of the commands writes to its standard error file,
2033 then `exec` will return an error, and the error message
2034 will include the pipeline's output, followed by messages
2035 about abnormal terminations (if any), followed by the standard error
2038 If the last character of the result or error message
2039 is a newline then that character is deleted from the result
2040 or error message for consistency with normal
2043 An +'arg'+ may have one of the following special forms:
2046 The standard output of the last command in the pipeline
2047 is redirected to the file. In this situation `exec`
2048 will normally return an empty string.
2051 As above, but append to the file.
2054 The standard output of the last command in the pipeline is
2055 redirected to the given (writable) file descriptor (e.g. stdout,
2056 stderr, or the result of `open`). In this situation `exec`
2057 will normally return an empty string.
2060 The standard error of the last command in the pipeline
2061 is redirected to the file.
2064 As above, but append to the file.
2067 The standard error of the last command in the pipeline is
2068 redirected to the given (writable) file descriptor.
2071 The standard error of the last command in the pipeline is
2072 redirected to the same file descriptor as the standard output.
2075 Both the standard output and standard error of the last command
2076 in the pipeline is redirected to the file.
2079 As above, but append to the file.
2082 The standard input of the first command in the pipeline
2083 is taken from the file.
2086 The standard input of the first command is taken as the
2087 given immediate value.
2090 The standard input of the first command in the pipeline
2091 is taken from the given (readable) file descriptor.
2093 If there is no redirection of standard input, standard error
2094 or standard output, these are connected to the corresponding
2095 input or output of the application.
2097 If the last +'arg'+ is +&+ then the command will be
2098 executed in background.
2099 In this case the standard output from the last command
2100 in the pipeline will
2101 go to the application's standard output unless
2102 redirected in the command, and error output from all
2103 the commands in the pipeline will go to the application's
2104 standard error file. The return value of exec in this case
2105 is a list of process ids (pids) in the pipeline.
2107 Each +'arg'+ becomes one word for a command, except for
2108 +|+, +<+, +<<+, +>+, and +&+ arguments, and the
2109 arguments that follow +<+, +<<+, and +>+.
2111 The first word in each command is taken as the command name;
2112 the directories in the PATH environment variable are searched for
2113 an executable by the given name.
2115 No `glob` expansion or other shell-like substitutions
2116 are performed on the arguments to commands.
2118 If the command fails, the global $::errorCode (and the -errorcode
2119 option in `catch`) will be set to a list, as follows:
2121 +*CHILDKILLED* 'pid sigName msg'+::
2122 This format is used when a child process has been killed
2123 because of a signal. The pid element will be the process's
2124 identifier (in decimal). The sigName element will be the
2125 symbolic name of the signal that caused the process to
2126 terminate; it will be one of the names from the include
2127 file signal.h, such as SIGPIPE. The msg element will be a
2128 short human-readable message describing the signal, such
2129 as "write on pipe with no readers" for SIGPIPE.
2131 +*CHILDSUSP* 'pid sigName msg'+::
2132 This format is used when a child process has been suspended
2133 because of a signal. The pid element will be the process's
2134 identifier, in decimal. The sigName element will be the
2135 symbolic name of the signal that caused the process to
2136 suspend; this will be one of the names from the include
2137 file signal.h, such as SIGTTIN. The msg element will be a
2138 short human-readable message describing the signal, such
2139 as "background tty read" for SIGTTIN.
2141 +*CHILDSTATUS* 'pid code'+::
2142 This format is used when a child process has exited with a
2143 non-zero exit status. The pid element will be the process's
2144 identifier (in decimal) and the code element will be the
2145 exit code returned by the process (also in decimal).
2147 The environment for the executed command is set from $::env (unless
2148 this variable is unset, in which case the original environment is used).
2152 +*exists ?-var|-proc|-command?* 'name'+
2154 Checks the existence of the given variable, procedure or command
2155 respectively and returns 1 if it exists or 0 if not. This command
2156 provides a more simplified/convenient version of `info exists`,
2157 `info procs` and `info commands`.
2159 If the type is omitted, a type of '-var' is used. The type may be abbreviated.
2163 +*exit* '?returnCode?'+
2165 Terminate the process, returning +'returnCode'+ to the
2166 parent as the exit status.
2168 If +'returnCode'+ isn't specified then it defaults
2171 Note that exit can be caught with `catch`.
2177 Calls the expression processor to evaluate +'arg'+, and returns
2178 the result as a string. See the section EXPRESSIONS above.
2180 Note that Jim supports a shorthand syntax for `expr` as +$(\...)+
2181 The following two are identical.
2183 set x [expr {3 * 2 + 1}]
2188 +*file* 'option name ?arg\...?'+
2190 Operate on a file or a file name. +'name'+ is the name of a file.
2192 +'option'+ indicates what to do with the file name. Any unique
2193 abbreviation for +'option'+ is acceptable. The valid options are:
2195 +*file atime* 'name'+::
2196 Return a decimal string giving the time at which file +'name'+
2197 was last accessed. The time is measured in the standard UNIX
2198 fashion as seconds from a fixed starting time (often January 1, 1970).
2199 If the file doesn't exist or its access time cannot be queried then an
2202 +*file copy ?-force?* 'source target'+::
2203 Copies file +'source'+ to file +'target'+. The source file must exist.
2204 The target file must not exist, unless +-force+ is specified.
2206 +*file delete ?-force?* 'name\...'+::
2207 Deletes file or directory +'name'+. If the file or directory doesn't exist, nothing happens.
2208 If it can't be deleted, an error is generated. Non-empty directories will not be deleted
2209 unless the +-force+ options is given. In this case no errors will be generated, even
2210 if the file/directory can't be deleted.
2212 +*file dirname* 'name'+::
2213 Return all of the characters in +'name'+ up to but not including
2214 the last slash character. If there are no slashes in +'name'+
2215 then return +.+ (a single dot). If the last slash in +'name'+ is its first
2216 character, then return +/+.
2218 +*file executable* 'name'+::
2219 Return '1' if file +'name'+ is executable by
2220 the current user, '0' otherwise.
2222 +*file exists* 'name'+::
2223 Return '1' if file +'name'+ exists and the current user has
2224 search privileges for the directories leading to it, '0' otherwise.
2226 +*file extension* 'name'+::
2227 Return all of the characters in +'name'+ after and including the
2228 last dot in +'name'+. If there is no dot in +'name'+ then return
2231 +*file isdirectory* 'name'+::
2232 Return '1' if file +'name'+ is a directory,
2235 +*file isfile* 'name'+::
2236 Return '1' if file +'name'+ is a regular file,
2239 +*file join* 'arg\...'+::
2240 Joins multiple path components. Note that if any components is
2241 an absolute path, the preceding components are ignored.
2242 Thus +"`file` join /tmp /root"+ returns +"/root"+.
2244 +*file lstat* 'name varName'+::
2245 Same as 'stat' option (see below) except uses the +'lstat'+
2246 kernel call instead of +'stat'+. This means that if +'name'+
2247 refers to a symbolic link the information returned in +'varName'+
2248 is for the link rather than the file it refers to. On systems that
2249 don't support symbolic links this option behaves exactly the same
2250 as the 'stat' option.
2252 +*file mkdir* 'dir1 ?dir2\...?'+::
2253 Creates each directory specified. For each pathname +'dir'+ specified,
2254 this command will create all non-existing parent directories
2255 as well as +'dir'+ itself. If an existing directory is specified,
2256 then no action is taken and no error is returned. Trying to
2257 overwrite an existing file with a directory will result in an
2258 error. Arguments are processed in the order specified, halting
2259 at the first error, if any.
2261 +*file mtime* 'name ?time?'+::
2262 Return a decimal string giving the time at which file +'name'+
2263 was last modified. The time is measured in the standard UNIX
2264 fashion as seconds from a fixed starting time (often January 1, 1970).
2265 If the file doesn't exist or its modified time cannot be queried then an
2266 error is generated. If +'time'+ is given, sets the modification time
2267 of the file to the given value.
2269 +*file normalize* 'name'+::
2270 Return the normalized path of +'name'+. See 'realpath(3)'.
2272 +*file owned* 'name'+::
2273 Return '1' if file +'name'+ is owned by the current user,
2276 +*file readable* 'name'+::
2277 Return '1' if file +'name'+ is readable by
2278 the current user, '0' otherwise.
2280 +*file readlink* 'name'+::
2281 Returns the value of the symbolic link given by +'name'+ (i.e. the
2282 name of the file it points to). If
2283 +'name'+ isn't a symbolic link or its value cannot be read, then
2284 an error is returned. On systems that don't support symbolic links
2285 this option is undefined.
2287 +*file rename* 'oldname' 'newname'+::
2288 Renames the file from the old name to the new name.
2290 +*file rootname* 'name'+::
2291 Return all of the characters in +'name'+ up to but not including
2292 the last '.' character in the name. If +'name'+ doesn't contain
2293 a dot, then return +'name'+.
2295 +*file size* 'name'+::
2296 Return a decimal string giving the size of file +'name'+ in bytes.
2297 If the file doesn't exist or its size cannot be queried then an
2300 +*file stat* 'name varName'+::
2301 Invoke the 'stat' kernel call on +'name'+, and use the
2302 variable given by +'varName'+ to hold information returned from
2304 +'varName'+ is treated as an array variable,
2305 and the following elements of that variable are set: 'atime',
2306 'ctime', 'dev', 'gid', 'ino', 'mode', 'mtime',
2307 'nlink', 'size', 'type', 'uid'.
2308 Each element except 'type' is a decimal string with the value of
2309 the corresponding field from the 'stat' return structure; see the
2310 manual entry for 'stat' for details on the meanings of the values.
2311 The 'type' element gives the type of the file in the same form
2312 returned by the command `file type`.
2313 This command returns an empty string.
2315 +*file tail* 'name'+::
2316 Return all of the characters in +'name'+ after the last slash.
2317 If +'name'+ contains no slashes then return +'name'+.
2319 +*file tempfile* '?template?'+::
2320 Creates and returns the name of a unique temporary file. If +'template'+ is omitted, a
2321 default template will be used to place the file in /tmp. See 'mkstemp(3)' for
2322 the format of the template and security concerns.
2324 +*file type* 'name'+::
2325 Returns a string giving the type of file +'name'+, which will be
2326 one of +file+, +directory+, +characterSpecial+,
2327 +blockSpecial+, +fifo+, +link+, or +socket+.
2329 +*file writable* 'name'+::
2330 Return '1' if file +'name'+ is writable by
2331 the current user, '0' otherwise.
2333 The `file` commands that return 0/1 results are often used in
2334 conditional or looping commands, for example:
2336 if {![file exists foo]} {
2337 error {bad file name}
2344 +*finalize* 'reference ?command?'+
2346 If +'command'+ is omitted, returns the finalizer command for the given reference.
2348 Otherwise, sets a new finalizer command for the given reference. +'command'+ may be
2349 the empty string to remove the current finalizer.
2351 The reference must be a valid reference create with the `ref`
2354 See GARBAGE COLLECTION, REFERENCES, LAMBDA for more detail.
2362 Flushes any output that has been buffered for +'fileId'+. +'fileId'+ must
2363 have been the return value from a previous call to `open`, or it may be
2364 +stdout+ or +stderr+ to access one of the standard I/O streams; it must
2365 refer to a file that was opened for writing. This command returns an
2370 +*for* 'start test next body'+
2372 `for` is a looping command, similar in structure to the C `for` statement.
2373 The +'start'+, +'next'+, and +'body'+ arguments must be Tcl command strings,
2374 and +'test'+ is an expression string.
2376 The `for` command first invokes the Tcl interpreter to execute +'start'+.
2377 Then it repeatedly evaluates +'test'+ as an expression; if the result is
2378 non-zero it invokes the Tcl interpreter on +'body'+, then invokes the Tcl
2379 interpreter on +'next'+, then repeats the loop. The command terminates
2380 when +'test'+ evaluates to 0.
2382 If a `continue` command is invoked within +'body'+ then any remaining
2383 commands in the current execution of +'body'+ are skipped; processing
2384 continues by invoking the Tcl interpreter on +'next'+, then evaluating
2385 +'test'+, and so on.
2387 If a `break` command is invoked within +'body'+ or +'next'+, then the `for`
2388 command will return immediately.
2390 The operation of `break` and `continue` are similar to the corresponding
2393 `for` returns an empty string.
2397 +*foreach* 'varName list body'+
2399 +*foreach* 'varList list ?varList2 list2 \...? body'+
2401 In this command, +'varName'+ is the name of a variable, +'list'+
2402 is a list of values to assign to +'varName'+, and +'body'+ is a
2403 collection of Tcl commands.
2405 For each field in +'list'+ (in order from left to right), `foreach` assigns
2406 the contents of the field to +'varName'+ (as if the `lindex` command
2407 had been used to extract the field), then calls the Tcl interpreter to
2410 If instead of being a simple name, +'varList'+ is used, multiple assignments
2411 are made each time through the loop, one for each element of +'varList'+.
2413 For example, if there are two elements in +'varList'+ and six elements in
2414 the list, the loop will be executed three times.
2416 If the length of the list doesn't evenly divide by the number of elements
2417 in +'varList'+, the value of the remaining variables in the last iteration
2418 of the loop are undefined.
2420 The `break` and `continue` statements may be invoked inside +'body'+,
2421 with the same effect as in the `for` command.
2423 `foreach` returns an empty string.
2427 +*format* 'formatString ?arg \...?'+
2429 This command generates a formatted string in the same way as the
2430 C 'sprintf' procedure (it uses 'sprintf' in its
2431 implementation). +'formatString'+ indicates how to format
2432 the result, using +%+ fields as in 'sprintf', and the additional
2433 arguments, if any, provide values to be substituted into the result.
2435 All of the 'sprintf' options are valid; see the 'sprintf'
2436 man page for details. Each +'arg'+ must match the expected type
2437 from the +%+ field in +'formatString'+; the `format` command
2438 converts each argument to the correct type (floating, integer, etc.)
2439 before passing it to 'sprintf' for formatting.
2441 The only unusual conversion is for +%c+; in this case the argument
2442 must be a decimal string, which will then be converted to the corresponding
2443 ASCII character value.
2445 `format` does backslash substitution on its +'formatString'+
2446 argument, so backslash sequences in +'formatString'+ will be handled
2447 correctly even if the argument is in braces.
2449 The return value from `format` is the formatted string.
2453 +*getref* 'reference'+
2455 Returns the string associated with +'reference'+. The reference must
2456 be a valid reference create with the `ref` command.
2458 See GARBAGE COLLECTION, REFERENCES, LAMBDA for more detail.
2462 +*gets* 'fileId ?varName?'+
2464 +'fileId' *gets* '?varName?'+
2466 Reads the next line from the file given by +'fileId'+ and discards
2467 the terminating newline character.
2469 If +'varName'+ is specified, then the line is placed in the variable
2470 by that name and the return value is a count of the number of characters
2471 read (not including the newline).
2473 If the end of the file is reached before reading
2474 any characters then -1 is returned and +'varName'+ is set to an
2477 If +'varName'+ is not specified then the return value will be
2478 the line (minus the newline character) or an empty string if
2479 the end of the file is reached before reading any characters.
2481 An empty string will also be returned if a line contains no characters
2482 except the newline, so `eof` may have to be used to determine
2483 what really happened.
2485 If the last character in the file is not a newline character, then
2486 `gets` behaves as if there were an additional newline character
2487 at the end of the file.
2489 +'fileId'+ must be +stdin+ or the return value from a previous
2490 call to `open`; it must refer to a file that was opened
2495 +*glob* ?*-nocomplain*? 'pattern ?pattern \...?'+
2497 This command performs filename globbing, using csh rules. The returned
2498 value from `glob` is the list of expanded filenames.
2500 If +-nocomplain+ is specified as the first argument then an empty
2501 list may be returned; otherwise an error is returned if the expanded
2502 list is empty. The +-nocomplain+ argument must be provided
2503 exactly: an abbreviation will not be accepted.
2508 +*global* 'varName ?varName \...?'+
2510 This command is ignored unless a Tcl procedure is being interpreted.
2511 If so, then it declares each given +'varName'+ to be a global variable
2512 rather than a local one. For the duration of the current procedure
2513 (and only while executing in the current procedure), any reference to
2514 +'varName'+ will be bound to a global variable instead
2517 An alternative to using `global` is to use the +::+ prefix
2518 to explicitly name a variable in the global scope.
2522 +*if* 'expr1' ?*then*? 'body1' *elseif* 'expr2' ?*then*? 'body2' *elseif* \... ?*else*? ?'bodyN'?+
2524 The `if` command evaluates +'expr1'+ as an expression (in the same way
2525 that `expr` evaluates its argument). The value of the expression must
2526 be numeric; if it is non-zero then +'body1'+ is executed by passing it to
2527 the Tcl interpreter.
2529 Otherwise +'expr2'+ is evaluated as an expression and if it is non-zero
2530 then +'body2'+ is executed, and so on.
2532 If none of the expressions evaluates to non-zero then +'bodyN'+ is executed.
2534 The +then+ and +else+ arguments are optional "noise words" to make the
2535 command easier to read.
2537 There may be any number of +elseif+ clauses, including zero. +'bodyN'+
2538 may also be omitted as long as +else+ is omitted too.
2540 The return value from the command is the result of the body script that
2541 was executed, or an empty string if none of the expressions was non-zero
2542 and there was no +'bodyN'+.
2546 +*incr* 'varName ?increment?'+
2548 Increment the value stored in the variable whose name is +'varName'+.
2549 The value of the variable must be integral.
2551 If +'increment'+ is supplied then its value (which must be an
2552 integer) is added to the value of variable +'varName'+; otherwise
2553 1 is added to +'varName'+.
2555 The new value is stored as a decimal string in variable +'varName'+
2556 and also returned as result.
2558 If the variable does not exist, the variable is implicitly created
2559 and set to +0+ first.
2564 +*info* 'option ?arg\...?'+::
2566 Provide information about various internals to the Tcl interpreter.
2567 The legal +'option'+'s (which may be abbreviated) are:
2569 +*info args* 'procname'+::
2570 Returns a list containing the names of the arguments to procedure
2571 +'procname'+, in order. +'procname'+ must be the name of a
2572 Tcl command procedure.
2574 +*info alias* 'command'+::
2575 +'command'+ must be an alias created with `alias`. In which case the target
2576 command and arguments, as passed to `alias` are returned.
2578 +*info body* 'procname'+::
2579 Returns the body of procedure +'procname'+. +'procname'+ must be
2580 the name of a Tcl command procedure.
2583 Returns a list of all open file handles from `open` or `socket`
2585 +*info commands* ?'pattern'?+::
2586 If +'pattern'+ isn't specified, returns a list of names of all the
2587 Tcl commands, including both the built-in commands written in C and
2588 the command procedures defined using the `proc` command.
2589 If +'pattern'+ is specified, only those names matching +'pattern'+
2590 are returned. Matching is determined using the same rules as for
2593 +*info complete* 'command' ?'missing'?+::
2594 Returns 1 if +'command'+ is a complete Tcl command in the sense of
2595 having no unclosed quotes, braces, brackets or array element names,
2596 If the command doesn't appear to be complete then 0 is returned.
2597 This command is typically used in line-oriented input environments
2598 to allow users to type in commands that span multiple lines; if the
2599 command isn't complete, the script can delay evaluating it until additional
2600 lines have been typed to complete the command. If +'varName'+ is specified, the
2601 missing character is stored in the variable with that name.
2603 +*info exists* 'varName'+::
2604 Returns '1' if the variable named +'varName'+ exists in the
2605 current context (either as a global or local variable), returns '0'
2608 +*info frame* ?'number'?+::
2609 If +'number'+ is not specified, this command returns a number
2610 which is the same result as `info level` - the current stack frame level.
2611 If +'number'+ is specified, then the result is a list consisting of the procedure,
2612 filename and line number for the procedure call at level +'number'+ on the stack.
2613 If +'number'+ is positive then it selects a particular stack level (1 refers
2614 to the top-most active procedure, 2 to the procedure it called, and
2615 so on); otherwise it gives a level relative to the current level
2616 (0 refers to the current procedure, -1 to its caller, and so on).
2617 The level has an identical meaning to `info level`.
2619 +*info globals* ?'pattern'?+::
2620 If +'pattern'+ isn't specified, returns a list of all the names
2621 of currently-defined global variables.
2622 If +'pattern'+ is specified, only those names matching +'pattern'+
2623 are returned. Matching is determined using the same rules as for
2627 An alias for `os.gethostname` for compatibility with Tcl 6.x
2629 +*info level* ?'number'?+::
2630 If +'number'+ is not specified, this command returns a number
2631 giving the stack level of the invoking procedure, or 0 if the
2632 command is invoked at top-level. If +'number'+ is specified,
2633 then the result is a list consisting of the name and arguments for the
2634 procedure call at level +'number'+ on the stack. If +'number'+
2635 is positive then it selects a particular stack level (1 refers
2636 to the top-most active procedure, 2 to the procedure it called, and
2637 so on); otherwise it gives a level relative to the current level
2638 (0 refers to the current procedure, -1 to its caller, and so on).
2639 See the `uplevel` command for more information on what stack
2642 +*info locals* ?'pattern'?+::
2643 If +'pattern'+ isn't specified, returns a list of all the names
2644 of currently-defined local variables, including arguments to the
2645 current procedure, if any. Variables defined with the `global`
2646 and `upvar` commands will not be returned. If +'pattern'+ is
2647 specified, only those names matching +'pattern'+ are returned.
2648 Matching is determined using the same rules as for `string match`.
2650 +*info nameofexecutable*+::
2651 Returns the name of the binary file from which the application
2652 was invoked. A full path will be returned, unless the path
2653 can't be determined, in which case the empty string will be returned.
2655 +*info procs* ?'pattern'?+::
2656 If +'pattern'+ isn't specified, returns a list of all the
2657 names of Tcl command procedures.
2658 If +'pattern'+ is specified, only those names matching +'pattern'+
2659 are returned. Matching is determined using the same rules as for
2662 +*info references*+::
2663 Returns a list of all references which have not yet been garbage
2666 +*info returncodes* ?'code'?+::
2667 Returns a list representing the mapping of standard return codes
2668 to names. e.g. +{0 ok 1 error 2 return \...}+. If a code is given,
2669 instead returns the name for the given code.
2672 If a Tcl script file is currently being evaluated (i.e. there is a
2673 call to 'Jim_EvalFile' active or there is an active invocation
2674 of the `source` command), then this command returns the name
2675 of the innermost file being processed. Otherwise the command returns an
2678 +*info source* 'script'+::
2679 Returns the original source location of the given script as a list of
2680 +{filename linenumber}+. If the source location can't be determined, the
2681 list +{{} 0}+ is returned.
2683 +*info stacktrace*+::
2684 After an error is caught with `catch`, returns the stack trace as a list
2685 of +{procedure filename line \...}+.
2687 +*info statics* 'procname'+::
2688 Returns a dictionary of the static variables of procedure
2689 +'procname'+. +'procname'+ must be the name of a Tcl command
2690 procedure. An empty dictionary is returned if the procedure has
2691 no static variables.
2694 Returns the version number for this version of Jim in the form +*x.yy*+.
2696 +*info vars* ?'pattern'?+::
2697 If +'pattern'+ isn't specified,
2698 returns a list of all the names of currently-visible variables, including
2699 both locals and currently-visible globals.
2700 If +'pattern'+ is specified, only those names matching +'pattern'+
2701 are returned. Matching is determined using the same rules as for
2706 +*join* 'list ?joinString?'+
2708 The +'list'+ argument must be a valid Tcl list. This command returns the
2709 string formed by joining all of the elements of +'list'+ together with
2710 +'joinString'+ separating each adjacent pair of elements.
2712 The +'joinString'+ argument defaults to a space character.
2716 +*kill* ?'SIG'|*-0*? 'pid'+
2718 Sends the given signal to the process identified by +'pid'+.
2720 The signal may be specified by name or number in one of the following forms:
2728 The signal name may be in either upper or lower case.
2730 The special signal name +-0+ simply checks that a signal +'could'+ be sent.
2732 If no signal is specified, SIGTERM is used.
2734 An error is raised if the signal could not be delivered.
2738 +*lambda* 'args ?statics? body'+
2740 The `lambda` command is identical to `proc`, except rather than
2741 creating a named procedure, it creates an anonymous procedure and returns
2742 the name of the procedure.
2744 See `proc` and GARBAGE COLLECTION, REFERENCES, LAMBDA for more detail.
2748 +*lappend* 'varName value ?value value \...?'+
2750 Treat the variable given by +'varName'+ as a list and append each of
2751 the +'value'+ arguments to that list as a separate element, with spaces
2754 If +'varName'+ doesn't exist, it is created as a list with elements given
2755 by the +'value'+ arguments. `lappend` is similar to `append` except that
2756 each +'value'+ is appended as a list element rather than raw text.
2758 This command provides a relatively efficient way to build up large lists.
2763 is much more efficient than
2765 set a [concat $a [list $b]]
2771 +*lassign* 'list varName ?varName \...?'+
2773 This command treats the value +'list'+ as a list and assigns successive elements from that list to
2774 the variables given by the +'varName'+ arguments in order. If there are more variable names than
2775 list elements, the remaining variables are set to the empty string. If there are more list ele-
2776 ments than variables, a list of unassigned elements is returned.
2778 jim> lassign {1 2 3} a b; puts a=$a,b=$b
2784 +*local* 'cmd ?arg\...?'+
2786 First, `local` evaluates +'cmd'+ with the given arguments. The return value must
2787 be the name of an existing command, which is marked as having local scope.
2788 This means that when the current procedure exits, the specified
2789 command is deleted. This can be useful with `lambda`, local procedures or
2790 to automatically close a filehandle.
2792 In addition, if a command already exists with the same name,
2793 the existing command will be kept rather than deleted, and may be called
2794 via `upcall`. The previous command will be restored when the current
2795 procedure exits. See `upcall` for more details.
2797 In this example, a local procedure is created. Note that the procedure
2798 continues to have global scope while it is active.
2801 # proc ... returns "inner" which is marked local
2802 local proc inner {} {
2803 # will be deleted when 'outer' exits
2810 In this example, the lambda is deleted at the end of the procedure rather
2811 than waiting until garbage collection.
2814 set x [lambda inner {args} {
2815 # will be deleted when 'outer' exits
2817 # Use 'function' here which simply returns $x
2826 +*loop* 'var first limit ?incr? body'+
2828 Similar to `for` except simpler and possibly more efficient.
2829 With a positive increment, equivalent to:
2831 for {set var $first} {$var < $limit} {incr var $incr} $body
2833 If +'incr'+ is not specified, 1 is used.
2834 Note that setting the loop variable inside the loop does not
2835 affect the loop count.
2839 +*lindex* 'list index'+
2841 Treats +'list'+ as a Tcl list and returns element +'index'+ from it
2842 (0 refers to the first element of the list).
2843 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
2845 In extracting the element, +'lindex'+ observes the same rules concerning
2846 braces and quotes and backslashes as the Tcl command interpreter; however,
2847 variable substitution and command substitution do not occur.
2849 If +'index'+ is negative or greater than or equal to the number of elements
2850 in +'value'+, then an empty string is returned.
2854 +*linsert* 'list index element ?element element \...?'+
2856 This command produces a new list from +'list'+ by inserting all
2857 of the +'element'+ arguments just before the element +'index'+
2858 of +'list'+. Each +'element'+ argument will become
2859 a separate element of the new list. If +'index'+ is less than
2860 or equal to zero, then the new elements are inserted at the
2861 beginning of the list. If +'index'+ is greater than or equal
2862 to the number of elements in the list, then the new elements are
2863 appended to the list.
2865 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
2870 +*list* 'arg ?arg \...?'+
2872 This command returns a list comprised of all the arguments, +'arg'+. Braces
2873 and backslashes get added as necessary, so that the `lindex` command
2874 may be used on the result to re-extract the original arguments, and also
2875 so that `eval` may be used to execute the resulting list, with
2876 +'arg1'+ comprising the command's name and the other args comprising
2877 its arguments. `list` produces slightly different results than
2878 `concat`: `concat` removes one level of grouping before forming
2879 the list, while `list` works directly from the original arguments.
2880 For example, the command
2882 list a b {c d e} {f {g h}}
2886 a b {c d e} {f {g h}}
2888 while `concat` with the same arguments will return
2896 Treats +'list'+ as a list and returns a decimal string giving
2897 the number of elements in it.
2901 +*lset* 'varName ?index ..? newValue'+
2903 Sets an element in a list.
2905 The `lset` command accepts a parameter, +'varName'+, which it interprets
2906 as the name of a variable containing a Tcl list. It also accepts
2907 zero or more indices into the list. Finally, it accepts a new value
2908 for an element of varName. If no indices are presented, the command
2911 lset varName newValue
2913 In this case, newValue replaces the old value of the variable
2916 When presented with a single index, the `lset` command
2917 treats the content of the varName variable as a Tcl list. It addresses
2918 the index'th element in it (0 refers to the first element of the
2919 list). When interpreting the list, `lset` observes the same rules
2920 concerning braces and quotes and backslashes as the Tcl command
2921 interpreter; however, variable substitution and command substitution
2922 do not occur. The command constructs a new list in which the
2923 designated element is replaced with newValue. This new list is
2924 stored in the variable varName, and is also the return value from
2927 If index is negative or greater than or equal to the number of
2928 elements in $varName, then an error occurs.
2930 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
2932 If additional index arguments are supplied, then each argument is
2933 used in turn to address an element within a sublist designated by
2934 the previous indexing operation, allowing the script to alter
2935 elements in sublists. The command,
2939 replaces element 2 of sublist 1 with +'newValue'+.
2941 The integer appearing in each index argument must be greater than
2942 or equal to zero. The integer appearing in each index argument must
2943 be strictly less than the length of the corresponding list. In other
2944 words, the `lset` command cannot change the size of a list. If an
2945 index is outside the permitted range, an error is reported.
2950 +*lmap* 'varName list body'+
2952 +*lmap* 'varList list ?varList2 list2 \...? body'+
2954 `lmap` is a "collecting" `foreach` which returns a list of its results.
2958 jim> lmap i {1 2 3 4 5} {expr $i*$i}
2960 jim> lmap a {1 2 3} b {A B C} {list $a $b}
2963 If the body invokes `continue`, no value is added for this iteration.
2964 If the body invokes `break`, the loop ends and no more values are added.
2970 Loads the dynamic extension, +'filename'+. Generally the filename should have
2971 the extension +.so+. The initialisation function for the module must be based
2972 on the name of the file. For example loading +hwaccess.so+ will invoke
2973 the initialisation function, +Jim_hwaccessInit+. Normally the `load` command
2974 should not be used directly. Instead it is invoked automatically by `package require`.
2978 +*lrange* 'list first last'+
2980 +'list'+ must be a valid Tcl list. This command will return a new
2981 list consisting of elements +'first'+ through +'last'+, inclusive.
2983 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
2985 If +'last'+ is greater than or equal to the number of elements
2986 in the list, then it is treated as if it were +end+.
2988 If +'first'+ is greater than +'last'+ then an empty string
2991 Note: +"`lrange` 'list first first'"+ does not always produce the
2992 same result as +"`lindex` 'list first'"+ (although it often does
2993 for simple fields that aren't enclosed in braces); it does, however,
2994 produce exactly the same results as +"`list` [`lindex` 'list first']"+
2999 +*lreplace* 'list first last ?element element \...?'+
3001 Returns a new list formed by replacing one or more elements of
3002 +'list'+ with the +'element'+ arguments.
3004 +'first'+ gives the index in +'list'+ of the first element
3007 If +'first'+ is less than zero then it refers to the first
3008 element of +'list'+; the element indicated by +'first'+
3009 must exist in the list.
3011 +'last'+ gives the index in +'list'+ of the last element
3012 to be replaced; it must be greater than or equal to +'first'+.
3014 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
3016 The +'element'+ arguments specify zero or more new arguments to
3017 be added to the list in place of those that were deleted.
3019 Each +'element'+ argument will become a separate element of
3022 If no +'element'+ arguments are specified, then the elements
3023 between +'first'+ and +'last'+ are simply deleted.
3027 +*lrepeat* 'number element1 ?element2 \...?'+
3029 Build a list by repeating elements +'number'+ times (which must be
3030 a positive integer).
3039 Returns the list in reverse order.
3041 jim> lreverse {1 2 3}
3046 +*lsearch* '?options? list pattern'+
3048 This command searches the elements +'list'+ to see if one of them matches +'pattern'+. If so, the
3049 command returns the index of the first matching element (unless the options +-all+, +-inline+ or +-bool+ are
3050 specified.) If not, the command returns -1. The option arguments indicates how the elements of
3051 the list are to be matched against pattern and must have one of the values below:
3053 *Note* that this command is different from Tcl in that default match type is +-exact+ rather than +-glob+.
3056 +'pattern'+ is a literal string that is compared for exact equality against each list element.
3057 This is the default.
3060 +'pattern'+ is a glob-style pattern which is matched against each list element using the same
3061 rules as the string match command.
3064 +'pattern'+ is treated as a regular expression and matched against each list element using
3065 the rules described by `regexp`.
3068 Changes the result to be the list of all matching indices (or all matching values if
3069 +-inline+ is specified as well). If indices are returned, the indices will be in numeric
3070 order. If values are returned, the order of the values will be the order of those values
3071 within the input list.
3074 The matching value is returned instead of its index (or an empty string if no value
3075 matches). If +-all+ is also specified, then the result of the command is the list of all
3076 values that matched. The +-inline+ and +-bool+ options are mutually exclusive.
3079 Changes the result to '1' if a match was found, or '0' otherwise. If +-all+ is also specified,
3080 the result will be a list of '0' and '1' for each element of the list depending upon whether
3081 the corresponding element matches. The +-inline+ and +-bool+ options are mutually exclusive.
3084 This negates the sense of the match, returning the index (or value
3085 if +-inline+ is specified) of the first non-matching value in the
3086 list. If +-bool+ is also specified, the '0' will be returned if a
3087 match is found, or '1' otherwise. If +-all+ is also specified,
3088 non-matches will be returned rather than matches.
3091 Causes comparisons to be handled in a case-insensitive manner.
3095 +*lsort* ?*-index* 'listindex'? ?*-integer*|*-command* 'cmdname'? ?*-decreasing*|*-increasing*? 'list'+
3097 Sort the elements of +'list'+, returning a new list in sorted order.
3098 By default, ASCII sorting is used, with the result in increasing order.
3100 If +-integer+ is specified, numeric sorting is used.
3102 If +-command 'cmdname'+ is specified, +'cmdname'+ is treated as a command
3103 name. For each comparison, +'cmdname $value1 $value2+' is called which
3104 should compare the values and return an integer less than, equal
3105 to, or greater than zero if the +'$value1'+ is to be considered less
3106 than, equal to, or greater than +'$value2'+, respectively.
3108 If +-decreasing+ is specified, the resulting list is in the opposite
3109 order to what it would be otherwise. +-increasing+ is the default.
3111 If +-index 'listindex'+ is specified, each element of the list is treated as a list and
3112 the given index is extracted from the list for comparison. The list index may
3113 be any valid list index, such as +1+, +end+ or +end-2+.
3115 If +-index 'listindex'+ is specified, each element of the list is treated as a list and
3116 the given index is extracted from the list for comparison. The list index may
3117 be any valid list index, such as +1+, +end+ or +end-2+.
3121 +*open* 'fileName ?access?'+
3123 +*open* '|command-pipeline ?access?'+
3125 Opens a file and returns an identifier
3126 that may be used in future invocations
3127 of commands like `read`, `puts`, and `close`.
3128 +'fileName'+ gives the name of the file to open.
3130 The +'access'+ argument indicates the way in which the file is to be accessed.
3131 It may have any of the following values:
3134 Open the file for reading only; the file must already exist.
3137 Open the file for both reading and writing; the file must
3141 Open the file for writing only. Truncate it if it exists. If it doesn't
3142 exist, create a new file.
3145 Open the file for reading and writing. Truncate it if it exists.
3146 If it doesn't exist, create a new file.
3149 Open the file for writing only. The file must already exist, and the file
3150 is positioned so that new data is appended to the file.
3153 Open the file for reading and writing. If the file doesn't
3154 exist, create a new empty file. Set the initial access position
3155 to the end of the file.
3157 +'access'+ defaults to 'r'.
3159 If a file is opened for both reading and writing, then `seek`
3160 must be invoked between a read and a write, or vice versa.
3162 If the first character of +'fileName'+ is "|" then the remaining
3163 characters of +'fileName'+ are treated as a list of arguments that
3164 describe a command pipeline to invoke, in the same style as the
3165 arguments for exec. In this case, the channel identifier returned
3166 by open may be used to write to the command's input pipe or read
3167 from its output pipe, depending on the value of +'access'+. If write-only
3168 access is used (e.g. +'access'+ is 'w'), then standard output for the
3169 pipeline is directed to the current standard output unless overridden
3170 by the command. If read-only access is used (e.g. +'access'+ is r),
3171 standard input for the pipeline is taken from the current standard
3172 input unless overridden by the command.
3174 The `pid` command may be used to return the process ids of the commands
3175 forming the command pipeline.
3177 See also `socket`, `pid`, `exec`
3181 +*package provide* 'name ?version?'+
3183 Indicates that the current script provides the package named +'name'+.
3184 If no version is specified, '1.0' is used.
3186 Any script which provides a package may include this statement
3187 as the first statement, although it is not required.
3189 +*package require* 'name ?version?'*+
3191 Searches for the package with the given +'name'+ by examining each path
3192 in '$::auto_path' and trying to load '$path/$name.so' as a dynamic extension,
3193 or '$path/$name.tcl' as a script package.
3195 The first such file which is found is considered to provide the the package.
3196 (The version number is ignored).
3198 If '$name.so' exists, it is loaded with the `load` command,
3199 otherwise if '$name.tcl' exists it is loaded with the `source` command.
3201 If `load` or `source` fails, `package require` will fail immediately.
3202 No further attempt will be made to locate the file.
3210 The first form returns the process identifier of the current process.
3212 The second form accepts a handle returned by `open` and returns a list
3213 of the process ids forming the pipeline in the same form as `exec ... &`.
3214 If 'fileId' represents a regular file handle rather than a command pipeline,
3215 the empty string is returned instead.
3217 See also `open`, `exec`
3221 +*proc* 'name args ?statics? body'+
3223 The `proc` command creates a new Tcl command procedure, +'name'+.
3224 When the new command is invoked, the contents of +'body'+ will be executed.
3225 Tcl interpreter. +'args'+ specifies the formal arguments to the procedure.
3226 If specified, +'static'+, declares static variables which are bound to the
3229 See PROCEDURES for detailed information about Tcl procedures.
3231 The `proc` command returns +'name'+ (which is useful with `local`).
3233 When a procedure is invoked, the procedure's return value is the
3234 value specified in a `return` command. If the procedure doesn't
3235 execute an explicit `return`, then its return value is the value
3236 of the last command executed in the procedure's body.
3238 If an error occurs while executing the procedure body, then the
3239 procedure-as-a-whole will return that same error.
3243 +*puts* ?*-nonewline*? '?fileId? string'+
3245 +'fileId' *puts* ?*-nonewline*? 'string'+
3247 Writes the characters given by +'string'+ to the file given
3248 by +'fileId'+. +'fileId'+ must have been the return
3249 value from a previous call to `open`, or it may be
3250 +stdout+ or +stderr+ to refer to one of the standard I/O
3251 channels; it must refer to a file that was opened for
3254 In the first form, if no +'fileId'+ is specified then it defaults to +stdout+.
3255 `puts` normally outputs a newline character after +'string'+,
3256 but this feature may be suppressed by specifying the +-nonewline+
3259 Output to files is buffered internally by Tcl; the `flush`
3260 command may be used to force buffered characters to be output.
3266 Returns the path name of the current working directory.
3270 +*rand* '?min? ?max?'+
3272 Returns a random integer between +'min'+ (defaults to 0) and +'max'+
3273 (defaults to the maximum integer).
3275 If only one argument is given, it is interpreted as +'max'+.
3279 +*range* '?start? end ?step?'+
3281 Returns a list of integers starting at +'start'+ (defaults to 0)
3282 and ranging up to but not including +'end'+ in steps of +'step'+ defaults to 1).
3295 +*read* ?*-nonewline*? 'fileId'+
3297 +'fileId' *read* ?*-nonewline*?+
3299 +*read* 'fileId numBytes'+
3301 +'fileId' *read* 'numBytes'+
3304 In the first form, all of the remaining bytes are read from the file
3305 given by +'fileId'+; they are returned as the result of the command.
3306 If the +-nonewline+ switch is specified then the last
3307 character of the file is discarded if it is a newline.
3309 In the second form, the extra argument specifies how many bytes to read;
3310 exactly this many bytes will be read and returned, unless there are fewer than
3311 +'numBytes'+ bytes left in the file; in this case, all the remaining
3314 +'fileId'+ must be +stdin+ or the return value from a previous call
3315 to `open`; it must refer to a file that was opened for reading.
3319 +*regexp ?-nocase? ?-line? ?-indices? ?-start* 'offset'? *?-all? ?-inline? ?--?* 'exp string ?matchVar? ?subMatchVar subMatchVar \...?'+
3321 Determines whether the regular expression +'exp'+ matches part or
3322 all of +'string'+ and returns 1 if it does, 0 if it doesn't.
3324 See REGULAR EXPRESSIONS above for complete information on the
3325 syntax of +'exp'+ and how it is matched against +'string'+.
3327 If additional arguments are specified after +'string'+ then they
3328 are treated as the names of variables to use to return
3329 information about which part(s) of +'string'+ matched +'exp'+.
3330 +'matchVar'+ will be set to the range of +'string'+ that
3331 matched all of +'exp'+. The first +'subMatchVar'+ will contain
3332 the characters in +'string'+ that matched the leftmost parenthesized
3333 subexpression within +'exp'+, the next +'subMatchVar'+ will
3334 contain the characters that matched the next parenthesized
3335 subexpression to the right in +'exp'+, and so on.
3337 Normally, +'matchVar'+ and the each +'subMatchVar'+ are set to hold the
3338 matching characters from `string`, however see +-indices+ and
3341 If there are more values for +'subMatchVar'+ than parenthesized subexpressions
3342 within +'exp'+, or if a particular subexpression in +'exp'+ doesn't
3343 match the string (e.g. because it was in a portion of the expression
3344 that wasn't matched), then the corresponding +'subMatchVar'+ will be
3345 set to +"-1 -1"+ if +-indices+ has been specified or to an empty
3348 The following switches modify the behaviour of +'regexp'+
3351 Causes upper-case and lower-case characters to be treated as
3352 identical during the matching process.
3355 Use newline-sensitive matching. By default, newline
3356 is a completely ordinary character with no special meaning in
3357 either REs or strings. With this flag, +[^+ bracket expressions
3358 and +.+ never match newline, a +^+ anchor matches the null
3359 string after any newline in the string in addition to its normal
3360 function, and the +$+ anchor matches the null string before any
3361 newline in the string in addition to its normal function.
3364 Changes what is stored in the subMatchVars. Instead of
3365 storing the matching characters from string, each variable
3366 will contain a list of two decimal strings giving the indices
3367 in string of the first and last characters in the matching
3368 range of characters.
3370 +*-start* 'offset'+::
3371 Specifies a character index offset into the string at which to start
3372 matching the regular expression. If +-indices+ is
3373 specified, the indices will be indexed starting from the
3374 absolute beginning of the input string. +'offset'+ will be
3375 constrained to the bounds of the input string.
3378 Causes the regular expression to be matched as many times as possible
3379 in the string, returning the total number of matches found. If this
3380 is specified with match variables, they will contain information
3381 for the last match only.
3384 Causes the command to return, as a list, the data that would otherwise
3385 be placed in match variables. When using +-inline+, match variables
3386 may not be specified. If used with +-all+, the list will be concatenated
3387 at each iteration, such that a flat list is always returned. For
3388 each match iteration, the command will append the overall match
3389 data, plus one element for each subexpression in the regular
3393 Marks the end of switches. The argument following this one will be
3394 treated as +'exp'+ even if it starts with a +-+.
3398 +*regsub ?-nocase? ?-all? ?-line? ?-start* 'offset'? ?*--*? 'exp string subSpec ?varName?'+
3400 This command matches the regular expression +'exp'+ against
3401 +'string'+ using the rules described in REGULAR EXPRESSIONS
3404 If +'varName'+ is specified, the commands stores +'string'+ to +'varName'+
3405 with the substitutions detailed below, and returns the number of
3406 substitutions made (normally 1 unless +-all+ is specified).
3407 This is 0 if there were no matches.
3409 If +'varName'+ is not specified, the substituted string will be returned
3412 When copying +'string'+, the portion of +'string'+ that
3413 matched +'exp'+ is replaced with +'subSpec'+.
3414 If +'subSpec'+ contains a +&+ or +{backslash}0+, then it is replaced
3415 in the substitution with the portion of +'string'+ that
3418 If +'subSpec'+ contains a +{backslash}n+, where +'n'+ is a digit
3419 between 1 and 9, then it is replaced in the substitution with
3420 the portion of +'string'+ that matched the +'n'+\'-th
3421 parenthesized subexpression of +'exp'+.
3422 Additional backslashes may be used in +'subSpec'+ to prevent special
3423 interpretation of +&+ or +{backslash}0+ or +{backslash}n+ or
3426 The use of backslashes in +'subSpec'+ tends to interact badly
3427 with the Tcl parser's use of backslashes, so it's generally
3428 safest to enclose +'subSpec'+ in braces if it includes
3431 The following switches modify the behaviour of +'regsub'+
3434 Upper-case characters in +'string'+ are converted to lower-case
3435 before matching against +'exp'+; however, substitutions
3436 specified by +'subSpec'+ use the original unconverted form
3440 All ranges in +'string'+ that match +'exp'+ are found and substitution
3441 is performed for each of these ranges, rather than only the
3442 first. The +&+ and +{backslash}n+ sequences are handled for
3443 each substitution using the information from the corresponding
3447 Use newline-sensitive matching. By default, newline
3448 is a completely ordinary character with no special meaning in
3449 either REs or strings. With this flag, +[^+ bracket expressions
3450 and +.+ never match newline, a +^+ anchor matches the null
3451 string after any newline in the string in addition to its normal
3452 function, and the +$+ anchor matches the null string before any
3453 newline in the string in addition to its normal function.
3455 +*-start* 'offset'+::
3456 Specifies a character index offset into the string at which to
3457 start matching the regular expression. +'offset'+ will be
3458 constrained to the bounds of the input string.
3461 Marks the end of switches. The argument following this one will be
3462 treated as +'exp'+ even if it starts with a +-+.
3466 +*ref* 'string tag ?finalizer?'+
3468 Create a new reference containing +'string'+ of type +'tag'+.
3469 If +'finalizer'+ is specified, it is a command which will be invoked
3470 when the a garbage collection cycle runs and this reference is
3471 no longer accessible.
3473 The finalizer is invoked as:
3475 finalizer reference string
3477 See GARBAGE COLLECTION, REFERENCES, LAMBDA for more detail.
3481 +*rename* 'oldName newName'+
3483 Rename the command that used to be called +'oldName'+ so that it
3484 is now called +'newName'+. If +'newName'+ is an empty string
3485 (e.g. {}) then +'oldName'+ is deleted. The `rename` command
3486 returns an empty string as result.
3490 +*return* ?*-code* 'code'? ?*-errorinfo* 'stacktrace'? ?*-errorcode* 'errorcode'? ?*-level* 'n'? ?'value'?+
3492 Return immediately from the current procedure (or top-level command
3493 or `source` command), with +'value'+ as the return value. If +'value'+
3494 is not specified, an empty string will be returned as result.
3496 If +-code+ is specified (as either a number or ok, error, break,
3497 continue, signal, return or exit), this code will be used instead
3498 of +JIM_OK+. This is generally useful when implementing flow of control
3501 If +-level+ is specified and greater than 1, it has the effect of delaying
3502 the new return code from +-code+. This is useful when rethrowing an error
3503 from `catch`. See the implementation of try/catch in tclcompat.tcl for
3504 an example of how this is done.
3506 Note: The following options are only used when +-code+ is JIM_ERR.
3508 If +-errorinfo+ is specified (as returned from `info stacktrace`)
3509 it is used to initialize the stacktrace.
3511 If +-errorcode+ is specified, it is used to set the global variable $::errorCode.
3515 +*scan* 'string format varName1 ?varName2 \...?'+
3517 This command parses fields from an input string in the same fashion
3518 as the C 'sscanf' procedure. +'string'+ gives the input to be parsed
3519 and +'format'+ indicates how to parse it, using '%' fields as in
3520 'sscanf'. All of the 'sscanf' options are valid; see the 'sscanf'
3521 man page for details. Each +'varName'+ gives the name of a variable;
3522 when a field is scanned from +'string'+, the result is converted back
3523 into a string and assigned to the corresponding +'varName'+. The
3524 only unusual conversion is for '%c'. For '%c' conversions a single
3525 character value is converted to a decimal string, which is then
3526 assigned to the corresponding +'varName'+; no field width may be
3527 specified for this conversion.
3531 +*seek* 'fileId offset ?origin?'+
3533 +'fileId' *seek* 'offset ?origin?'+
3535 Change the current access position for +'fileId'+.
3536 The +'offset'+ and +'origin'+ arguments specify the position at
3537 which the next read or write will occur for +'fileId'+.
3538 +'offset'+ must be a number (which may be negative) and +'origin'+
3539 must be one of the following:
3542 The new access position will be +'offset'+ bytes from the start
3546 The new access position will be +'offset'+ bytes from the current
3547 access position; a negative +'offset'+ moves the access position
3548 backwards in the file.
3551 The new access position will be +'offset'+ bytes from the end of
3552 the file. A negative +'offset'+ places the access position before
3553 the end-of-file, and a positive +'offset'+ places the access position
3554 after the end-of-file.
3556 The +'origin'+ argument defaults to +start+.
3558 +'fileId'+ must have been the return value from a previous call to
3559 `open`, or it may be +stdin+, +stdout+, or +stderr+ to refer to one
3560 of the standard I/O channels.
3562 This command returns an empty string.
3566 +*set* 'varName ?value?'+
3568 Returns the value of variable +'varName'+.
3570 If +'value'+ is specified, then set the value of +'varName'+ to +'value'+,
3571 creating a new variable if one doesn't already exist, and return
3574 If +'varName'+ contains an open parenthesis and ends with a
3575 close parenthesis, then it refers to an array element: the characters
3576 before the open parenthesis are the name of the array, and the characters
3577 between the parentheses are the index within the array.
3578 Otherwise +'varName'+ refers to a scalar variable.
3580 If no procedure is active, then +'varName'+ refers to a global
3583 If a procedure is active, then +'varName'+ refers to a parameter
3584 or local variable of the procedure, unless the +'global'+ command
3585 has been invoked to declare +'varName'+ to be global.
3587 The +::+ prefix may also be used to explicitly reference a variable
3588 in the global scope.
3592 +*setref* 'reference string'+
3594 Store a new string in +'reference'+, replacing the existing string.
3595 The reference must be a valid reference create with the `ref`
3598 See GARBAGE COLLECTION, REFERENCES, LAMBDA for more detail.
3602 Command for signal handling.
3604 See `kill` for the different forms which may be used to specify signals.
3606 Commands which return a list of signal names do so using the canonical form:
3609 +*signal handle* ?'signals \...'?+::
3610 If no signals are given, returns a list of all signals which are currently
3612 If signals are specified, these are added to the list of signals currently
3615 +*signal ignore* ?'signals \...'?+::
3616 If no signals are given, returns a lists all signals which are currently
3618 If signals are specified, these are added to the list of signals
3619 currently being ignored. These signals are still delivered, but
3620 are not considered by `catch -signal` or `try -signal`. Use
3621 `signal check` to determine which signals have occurred but
3624 +*signal default* ?'signals \...'?+::
3625 If no signals are given, returns a lists all signals which are currently have
3626 the default behaviour.
3627 If signals are specified, these are added to the list of signals which have
3628 the default behaviour.
3630 +*signal check ?-clear?* ?'signals \...'?+::
3631 Returns a list of signals which have been delivered to the process
3632 but are 'ignored'. If signals are specified, only that set of signals will
3633 be checked, otherwise all signals will be checked.
3634 If +-clear+ is specified, any signals returned are removed and will not be
3635 returned by subsequent calls to `signal check` unless delivered again.
3637 +*signal throw* ?'signal'?+::
3638 Raises the given signal, which defaults to +SIGINT+ if not specified.
3639 The behaviour is identical to:
3643 Note that `signal handle` and `signal ignore` represent two forms of signal
3644 handling. `signal handle` is used in conjunction with `catch -signal` or `try -signal`
3645 to immediately abort execution when the signal is delivered. Alternatively, `signal ignore`
3646 is used in conjunction with `signal check` to handle signal synchronously. Consider the
3649 Prevent a processing from taking too long
3651 signal handle SIGALRM
3654 .. possibly long running process ..
3657 puts stderr "Process took too long"
3660 Handle SIGHUP to reconfigure:
3662 signal ignore SIGHUP
3664 ... handle configuration/reconfiguration ...
3665 while {[signal check -clear SIGHUP] eq ""} {
3666 ... do processing ..
3668 # Received SIGHUP, so reconfigure
3675 Pauses for the given number of seconds, which may be a floating
3676 point value less than one to sleep for less than a second, or an
3677 integer to sleep for one or more seconds.
3681 +*source* 'fileName'+
3683 Read file +'fileName'+ and pass the contents to the Tcl interpreter
3684 as a sequence of commands to execute in the normal fashion. The return
3685 value of `source` is the return value of the last command executed
3686 from the file. If an error occurs in executing the contents of the
3687 file, then the `source` command will return that error.
3689 If a `return` command is invoked from within the file, the remainder of
3690 the file will be skipped and the `source` command will return
3691 normally with the result from the `return` command.
3695 +*split* 'string ?splitChars?'+
3697 Returns a list created by splitting +'string'+ at each character
3698 that is in the +'splitChars'+ argument.
3700 Each element of the result list will consist of the
3701 characters from +'string'+ between instances of the
3702 characters in +'splitChars'+.
3704 Empty list elements will be generated if +'string'+ contains
3705 adjacent characters in +'splitChars'+, or if the first or last
3706 character of +'string'+ is in +'splitChars'+.
3708 If +'splitChars'+ is an empty string then each character of
3709 +'string'+ becomes a separate element of the result list.
3711 +'splitChars'+ defaults to the standard white-space characters.
3714 split "comp.unix.misc" .
3716 returns +'"comp unix misc"'+ and
3718 split "Hello world" {}
3720 returns +'"H e l l o { } w o r l d"'+.
3725 +*stackdump* 'stacktrace'+
3727 Creates a human readable representation of a stack trace.
3734 Returns a live stack trace as a list of +proc file line proc file line \...+.
3735 Iteratively uses `info frame` to create the stack trace. This stack trace is in the
3736 same form as produced by `catch` and `info stacktrace`
3738 See also `stackdump`.
3743 +*string* 'option arg ?arg \...?'+
3745 Perform one of several string operations, depending on +'option'+.
3746 The legal options (which may be abbreviated) are:
3748 +*string bytelength* 'string'+::
3749 Returns the length of the string in bytes. This will return
3750 the same value as `string length` if UTF-8 support is not enabled,
3751 or if the string is composed entirely of ASCII characters.
3752 See UTF-8 AND UNICODE.
3754 +*string byterange* 'string first last'+::
3755 Like `string range` except works on bytes rather than characters.
3756 These commands are identical if UTF-8 support is not enabled.
3758 +*string compare ?-nocase?* 'string1 string2'+::
3759 Perform a character-by-character comparison of strings +'string1'+ and
3760 +'string2'+ in the same way as the C 'strcmp' procedure. Return
3761 -1, 0, or 1, depending on whether +'string1'+ is lexicographically
3762 less than, equal to, or greater than +'string2'+.
3763 Performs a case-insensitive comparison if +-nocase+ is specified.
3765 +*string equal ?-nocase?* 'string1 string2'+::
3766 Returns 1 if the strings are equal, or 0 otherwise.
3767 Performs a case-insensitive comparison if +-nocase+ is specified.
3769 +*string first* 'string1 string2 ?firstIndex?'+::
3770 Search +'string2'+ for a sequence of characters that exactly match
3771 the characters in +'string1'+. If found, return the index of the
3772 first character in the first such match within +'string2'+. If not
3773 found, return -1. If +'firstIndex'+ is specified, matching will start
3774 from +'firstIndex'+ of +'string1'+.
3776 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'firstIndex'+.
3778 +*string index* 'string charIndex'+::
3779 Returns the +'charIndex'+'th character of the +'string'+
3780 argument. A +'charIndex'+ of 0 corresponds to the first
3781 character of the string.
3782 If +'charIndex'+ is less than 0 or greater than
3783 or equal to the length of the string then an empty string is
3786 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'charIndex'+.
3788 +*string is* 'class' ?*-strict*? 'string'+::
3789 Returns 1 if +'string'+ is a valid member of the specified character
3790 class, otherwise returns 0. If +-strict+ is specified, then an
3791 empty string returns 0, otherwise an empty string will return 1
3792 on any class. The following character classes are recognized
3793 (the class name can be abbreviated):
3795 +alnum+;; Any alphabet or digit character.
3796 +alpha+;; Any alphabet character.
3797 +ascii+;; Any character with a value less than 128 (those that are in the 7-bit ascii range).
3798 +control+;; Any control character.
3799 +digit+;; Any digit character.
3800 +double+;; Any of the valid forms for a double in Tcl, with optional surrounding whitespace.
3801 In case of under/overflow in the value, 0 is returned.
3802 +graph+;; Any printing character, except space.
3803 +integer+;; Any of the valid string formats for an integer value in Tcl, with optional surrounding whitespace.
3804 +lower+;; Any lower case alphabet character.
3805 +print+;; Any printing character, including space.
3806 +punct+;; Any punctuation character.
3807 +space+;; Any space character.
3808 +upper+;; Any upper case alphabet character.
3809 +xdigit+;; Any hexadecimal digit character ([0-9A-Fa-f]).
3811 Note that string classification does +'not'+ respect UTF-8. See UTF-8 AND UNICODE
3813 +*string last* 'string1 string2 ?lastIndex?'+::
3814 Search +'string2'+ for a sequence of characters that exactly match
3815 the characters in +'string1'+. If found, return the index of the
3816 first character in the last such match within +'string2'+. If there
3817 is no match, then return -1. If +'lastIndex'+ is specified, only characters
3818 up to +'lastIndex'+ of +'string2'+ will be considered in the match.
3820 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'lastIndex'+.
3822 +*string length* 'string'+::
3823 Returns a decimal string giving the number of characters in +'string'+.
3824 If UTF-8 support is enabled, this may be different than the number of bytes.
3825 See UTF-8 AND UNICODE
3827 +*string map ?-nocase?* 'mapping string'+::
3828 Replaces substrings in +'string'+ based on the key-value pairs in
3829 +'mapping'+, which is a list of +key value key value \...+ as in the form
3830 returned by `array get`. Each instance of a key in the string will be
3831 replaced with its corresponding value. If +-nocase+ is specified, then
3832 matching is done without regard to case differences. Both key and value may
3833 be multiple characters. Replacement is done in an ordered manner, so the
3834 key appearing first in the list will be checked first, and so on. +'string'+ is
3835 only iterated over once, so earlier key replacements will have no affect for
3836 later key matches. For example,
3838 string map {abc 1 ab 2 a 3 1 0} 1abcaababcabababc
3841 will return the string +01321221+.
3843 Note that if an earlier key is a prefix of a later one, it will completely mask the later
3844 one. So if the previous example is reordered like this,
3846 string map {1 0 ab 2 a 3 abc 1} 1abcaababcabababc
3849 it will return the string +02c322c222c+.
3851 +*string match ?-nocase?* 'pattern string'+::
3852 See if +'pattern'+ matches +'string'+; return 1 if it does, 0
3853 if it doesn't. Matching is done in a fashion similar to that
3854 used by the C-shell. For the two strings to match, their contents
3855 must be identical except that the following special sequences
3856 may appear in +'pattern'+:
3859 Matches any sequence of characters in +'string'+,
3860 including a null string.
3863 Matches any single character in +'string'+.
3866 Matches any character in the set given by +'chars'+.
3867 If a sequence of the form +'x-y'+ appears in +'chars'+,
3868 then any character between +'x'+ and +'y'+, inclusive,
3872 Matches the single character +'x'+. This provides a way of
3873 avoiding the special interpretation of the characters +{backslash}*?[]+
3876 Performs a case-insensitive comparison if +-nocase+ is specified.
3878 +*string range* 'string first last'+::
3879 Returns a range of consecutive characters from +'string'+, starting
3880 with the character whose index is +'first'+ and ending with the
3881 character whose index is +'last'+. An index of 0 refers to the
3882 first character of the string.
3884 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
3886 If +'first'+ is less than zero then it is treated as if it were zero, and
3887 if +'last'+ is greater than or equal to the length of the string then
3888 it is treated as if it were +end+. If +'first'+ is greater than
3889 +'last'+ then an empty string is returned.
3891 +*string repeat* 'string count'+::
3892 Returns a new string consisting of +'string'+ repeated +'count'+ times.
3894 +*string replace* 'string first last ?newstring?'+::
3895 Removes a range of consecutive characters from +'string'+, starting
3896 with the character whose index is +'first'+ and ending with the
3897 character whose index is +'last'+. If +'newstring'+ is specified,
3898 then it is placed in the removed character range. If +'first'+ is
3899 less than zero then it is treated as if it were zero, and if +'last'+
3900 is greater than or equal to the length of the string then it is
3901 treated as if it were +end+. If +'first'+ is greater than +'last'+
3902 or the length of the initial string, or +'last'+ is less than 0,
3903 then the initial string is returned untouched.
3905 +*string reverse* 'string'+::
3906 Returns a string that is the same length as +'string'+ but
3907 with its characters in the reverse order.
3909 +*string tolower* 'string'+::
3910 Returns a value equal to +'string'+ except that all upper case
3911 letters have been converted to lower case.
3913 +*string totitle* 'string'+::
3914 Returns a value equal to +'string'+ except that the first character
3915 is converted to title case (or upper case if there is no UTF-8 titlecase variant)
3916 and all remaining characters have been converted to lower case.
3918 +*string toupper* 'string'+::
3919 Returns a value equal to +'string'+ except that all lower case
3920 letters have been converted to upper case.
3922 +*string trim* 'string ?chars?'+::
3923 Returns a value equal to +'string'+ except that any leading
3924 or trailing characters from the set given by +'chars'+ are
3926 If +'chars'+ is not specified then white space is removed
3927 (spaces, tabs, newlines, and carriage returns).
3929 +*string trimleft* 'string ?chars?'+::
3930 Returns a value equal to +'string'+ except that any
3931 leading characters from the set given by +'chars'+ are
3933 If +'chars'+ is not specified then white space is removed
3934 (spaces, tabs, newlines, and carriage returns).
3936 +*string trimright* 'string ?chars?'+::
3937 Returns a value equal to +'string'+ except that any
3938 trailing characters from the set given by +'chars'+ are
3940 If +'chars'+ is not specified then white space is removed
3941 (spaces, tabs, newlines, and carriage returns).
3942 Null characters are always removed.
3946 +*subst ?-nobackslashes? ?-nocommands? ?-novariables?* 'string'+
3948 This command performs variable substitutions, command substitutions,
3949 and backslash substitutions on its string argument and returns the
3950 fully-substituted result. The substitutions are performed in exactly
3951 the same way as for Tcl commands. As a result, the string argument
3952 is actually substituted twice, once by the Tcl parser in the usual
3953 fashion for Tcl commands, and again by the subst command.
3955 If any of the +-nobackslashes+, +-nocommands+, or +-novariables+ are
3956 specified, then the corresponding substitutions are not performed.
3957 For example, if +-nocommands+ is specified, no command substitution
3958 is performed: open and close brackets are treated as ordinary
3959 characters with no special interpretation.
3961 *Note*: when it performs its substitutions, subst does not give any
3962 special treatment to double quotes or curly braces. For example,
3963 the following script returns +xyz \{44\}+, not +xyz \{$a\}+.
3971 +*switch* '?options? string pattern body ?pattern body \...?'+
3973 +*switch* '?options? string {pattern body ?pattern body \...?}'+
3975 The `switch` command matches its string argument against each of
3976 the pattern arguments in order. As soon as it finds a pattern that
3977 matches string it evaluates the following body and returns the
3978 result of that evaluation. If the last pattern argument is default
3979 then it matches anything. If no pattern argument matches string and
3980 no default is given, then the `switch` command returns an empty string.
3981 If the initial arguments to switch start with - then they are treated
3982 as options. The following options are currently supported:
3985 Use exact matching when comparing string to a
3986 pattern. This is the default.
3989 When matching string to the patterns, use glob-style
3990 matching (i.e. the same as implemented by the string
3994 When matching string to the patterns, use regular
3995 expression matching (i.e. the same as implemented
3996 by the regexp command).
3998 +-command 'commandname'+::
3999 When matching string to the patterns, use the given command, which
4000 must be a single word. The command is invoked as
4001 'commandname pattern string', or 'commandname -nocase pattern string'
4002 and must return 1 if matched, or 0 if not.
4005 Marks the end of options. The argument following
4006 this one will be treated as string even if it starts
4009 Two syntaxes are provided for the pattern and body arguments. The
4010 first uses a separate argument for each of the patterns and commands;
4011 this form is convenient if substitutions are desired on some of the
4012 patterns or commands. The second form places all of the patterns
4013 and commands together into a single argument; the argument must
4014 have proper list structure, with the elements of the list being the
4015 patterns and commands. The second form makes it easy to construct
4016 multi-line `switch` commands, since the braces around the whole list
4017 make it unnecessary to include a backslash at the end of each line.
4018 Since the pattern arguments are in braces in the second form, no
4019 command or variable substitutions are performed on them; this makes
4020 the behaviour of the second form different than the first form in
4023 If a body is specified as +-+ it means that the body for the next
4024 pattern should also be used as the body for this pattern (if the
4025 next pattern also has a body of +-+ then the body after that is
4026 used, and so on). This feature makes it possible to share a single
4027 body among several patterns.
4029 Below are some examples of `switch` commands:
4031 switch abc a - b {format 1} abc {format 2} default {format 3}
4035 switch -regexp aaab {
4055 +*tailcall* 'cmd ?arg\...?'+
4057 The `tailcall` command provides an optimised way of invoking a command whilst replacing
4058 the current call frame. This is similar to 'exec' in Bourne Shell.
4060 The following are identical except the first immediately replaces the current call frame.
4064 return [uplevel 1 [list a b c]]
4066 `tailcall` is useful as a dispatch mechanism:
4069 tailcall sub_$cmd {*}$args
4080 Returns a decimal string giving the current access position in
4083 +'fileId'+ must have been the return value from a previous call to
4084 `open`, or it may be +stdin+, +stdout+, or +stderr+ to refer to one
4085 of the standard I/O channels.
4089 +*throw* 'code ?msg?'+
4091 This command throws an exception (return) code along with an optional message.
4092 This command is mostly for convenient usage with `try`.
4094 The command +throw break+ is equivalent to +break+.
4095 The command +throw 20 message+ can be caught with an +on 20 \...+ clause to `try`.
4099 +*time* 'command ?count?'+
4101 This command will call the Tcl interpreter +'count'+
4102 times to execute +'command'+ (or once if +'count'+ isn't
4103 specified). It will then return a string of the form
4105 503 microseconds per iteration
4107 which indicates the average amount of time required per iteration,
4110 Time is measured in elapsed time, not CPU time.
4114 +*try* '?catchopts? tryscript' ?*on* 'returncodes {?resultvar? ?optsvar?} handlerscript \...'? ?*finally* 'finalscript'?+
4116 The `try` command is provided as a convenience for exception handling.
4118 This interpeter first evaluates +'tryscript'+ under the effect of the catch
4119 options +'catchopts'+ (e.g. +-signal -noexit --+, see `catch`).
4121 It then evaluates the script for the first matching 'on' handler
4122 (there many be zero or more) based on the return code from the `try`
4123 section. For example a normal +JIM_ERR+ error will be matched by
4124 an 'on error' handler.
4126 Finally, any +'finalscript'+ is evaluated.
4128 The result of this command is the result of +'tryscript'+, except in the
4129 case where an exception occurs in a matching 'on' handler script or the 'finally' script,
4130 in which case the result is this new exception.
4132 The specified +'returncodes'+ is a list of return codes either as names ('ok', 'error', 'break', etc.)
4135 If +'resultvar'+ and +'optsvar'+ are specified, they are set as for `catch` before evaluating
4136 the matching handler.
4143 } on {continue break} {} {
4144 error "Unexpected break/continue"
4145 } on error {msg opts} {
4146 puts "Dealing with error"
4147 return {*}$opts $msg
4149 puts "Got signal: $sig"
4154 If break, continue or error are raised, they are dealt with by the matching
4157 In any case, the file will be closed via the 'finally' clause.
4159 See also `throw`, `catch`, `return`, `error`.
4163 +*unknown* 'cmdName ?arg arg ...?'+
4165 This command doesn't actually exist as part of Tcl, but Tcl will
4166 invoke it if it does exist.
4168 If the Tcl interpreter encounters a command name for which there
4169 is not a defined command, then Tcl checks for the existence of
4170 a command named `unknown`.
4172 If there is no such command, then the interpreter returns an
4175 If the `unknown` command exists, then it is invoked with
4176 arguments consisting of the fully-substituted name and arguments
4177 for the original non-existent command.
4179 The `unknown` command typically does things like searching
4180 through library directories for a command procedure with the name
4181 +'cmdName'+, or expanding abbreviated command names to full-length,
4182 or automatically executing unknown commands as UNIX sub-processes.
4184 In some cases (such as expanding abbreviations) `unknown` will
4185 change the original command slightly and then (re-)execute it.
4186 The result of the `unknown` command is used as the result for
4187 the original non-existent command.
4191 +*unset ?-nocomplain? ?--?* '?name name ...?'+
4194 Each +'name'+ is a variable name, specified in any of the
4195 ways acceptable to the `set` command.
4197 If a +'name'+ refers to an element of an array, then that
4198 element is removed without affecting the rest of the array.
4200 If a +'name'+ consists of an array name with no parenthesized
4201 index, then the entire array is deleted.
4203 The `unset` command returns an empty string as result.
4205 An error occurs if any of the variables doesn't exist, unless '-nocomplain'
4206 is specified. The '--' argument may be specified to stop option processing
4207 in case the variable name may be '-nocomplain'.
4211 +*upcall* 'command ?args ...?'+
4213 May be used from within a proc defined as `local` `proc` in order to call
4214 the previous, hidden version of the same command.
4216 If there is no previous definition of the command, an error is returned.
4220 +*uplevel* '?level? command ?command ...?'+
4222 All of the +'command'+ arguments are concatenated as if they had
4223 been passed to `concat`; the result is then evaluated in the
4224 variable context indicated by +'level'+. `uplevel` returns
4225 the result of that evaluation. If +'level'+ is an integer, then
4226 it gives a distance (up the procedure calling stack) to move before
4227 executing the command. If +'level'+ consists of +\#+ followed by
4228 a number then the number gives an absolute level number. If +'level'+
4229 is omitted then it defaults to +1+. +'level'+ cannot be
4230 defaulted if the first +'command'+ argument starts with a digit or +#+.
4232 For example, suppose that procedure 'a' was invoked
4233 from top-level, and that it called 'b', and that 'b' called 'c'.
4234 Suppose that 'c' invokes the `uplevel` command. If +'level'+
4235 is +1+ or +#2+ or omitted, then the command will be executed
4236 in the variable context of 'b'. If +'level'+ is +2+ or +#1+
4237 then the command will be executed in the variable context of 'a'.
4239 If +'level'+ is '3' or +#0+ then the command will be executed
4240 at top-level (only global variables will be visible).
4241 The `uplevel` command causes the invoking procedure to disappear
4242 from the procedure calling stack while the command is being executed.
4243 In the above example, suppose 'c' invokes the command
4245 uplevel 1 {set x 43; d}
4247 where 'd' is another Tcl procedure. The `set` command will
4248 modify the variable 'x' in 'b's context, and 'd' will execute
4249 at level 3, as if called from 'b'. If it in turn executes
4254 then the `set` command will modify the same variable 'x' in 'b's
4255 context: the procedure 'c' does not appear to be on the call stack
4256 when 'd' is executing. The command `info level` may
4257 be used to obtain the level of the current procedure.
4259 `uplevel` makes it possible to implement new control
4260 constructs as Tcl procedures (for example, `uplevel` could
4261 be used to implement the `while` construct as a Tcl procedure).
4265 +*upvar* '?level? otherVar myVar ?otherVar myVar ...?'+
4267 This command arranges for one or more local variables in the current
4268 procedure to refer to variables in an enclosing procedure call or
4269 to global variables.
4271 +'level'+ may have any of the forms permitted for the `uplevel`
4272 command, and may be omitted if the first letter of the first +'otherVar'+
4273 isn't +#+ or a digit (it defaults to '1').
4275 For each +'otherVar'+ argument, `upvar` makes the variable
4276 by that name in the procedure frame given by +'level'+ (or at
4277 global level, if +'level'+ is +#0+) accessible
4278 in the current procedure by the name given in the corresponding
4281 The variable named by +'otherVar'+ need not exist at the time of the
4282 call; it will be created the first time +'myVar'+ is referenced, just like
4283 an ordinary variable.
4285 `upvar` may only be invoked from within procedures.
4287 `upvar` returns an empty string.
4289 The `upvar` command simplifies the implementation of call-by-name
4290 procedure calling and also makes it easier to build new control constructs
4292 For example, consider the following procedure:
4299 'add2' is invoked with an argument giving the name of a variable,
4300 and it adds two to the value of that variable.
4301 Although 'add2' could have been implemented using `uplevel`
4302 instead of `upvar`, `upvar` makes it simpler for 'add2'
4303 to access the variable in the caller's procedure frame.
4307 +*while* 'test body'+
4309 The +'while'+ command evaluates +'test'+ as an expression
4310 (in the same way that `expr` evaluates its argument).
4311 The value of the expression must be numeric; if it is non-zero
4312 then +'body'+ is executed by passing it to the Tcl interpreter.
4314 Once +'body'+ has been executed then +'test'+ is evaluated
4315 again, and the process repeats until eventually +'test'+
4316 evaluates to a zero numeric value. `continue`
4317 commands may be executed inside +'body'+ to terminate the current
4318 iteration of the loop, and `break`
4319 commands may be executed inside +'body'+ to cause immediate
4320 termination of the `while` command.
4322 The `while` command always returns an empty string.
4327 The following extensions may or may not be available depending upon
4328 what options were selected when Jim Tcl was built.
4331 posix: os.fork, os.wait, os.gethostname, os.getids, os.uptime
4332 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4334 Invokes 'fork(2)' and returns the result.
4336 +*os.wait -nohang* 'pid'+::
4337 Invokes waitpid(2), with WNOHANG if +-nohang+ is specified.
4338 Returns a list of 3 elements.
4340 {0 none 0} if -nohang is specified, and the process is still alive.
4342 {-1 error <error-description>} if the process does not exist or has already been waited for.
4344 {<pid> exit <exit-status>} if the process exited normally.
4346 {<pid> signal <signal-number>} if the process terminated on a signal.
4348 {<pid> other 0} otherwise (core dump, stopped, continued, etc.)
4350 +*os.gethostname*+::
4351 Invokes 'gethostname(3)' and returns the result.
4354 Returns the various user/group ids for the current process.
4357 uid 1000 euid 1000 gid 100 egid 100
4360 Returns the number of seconds since system boot. See description of 'uptime' in 'sysinfo(2)'.
4362 ANSI I/O (aio) and EVENTLOOP API
4363 --------------------------------
4364 Jim provides an alternative object-based API for I/O.
4366 See `open` and `socket` for commands which return an I/O handle.
4370 +$handle *read ?-nonewline?* '?len?'+::
4371 Read and return bytes from the stream. To eof if no len.
4373 +$handle *gets* '?var?'+::
4374 Read one line and return it or store it in the var
4376 +$handle *puts ?-nonewline?* 'str'+::
4377 Write the string, with newline unless -nonewline
4379 +$handle *copyto* 'tofd ?size?'+::
4380 Copy bytes to the file descriptor +'tofd'+. If +'size'+ is specified, at most
4381 that many bytes will be copied. Otherwise copying continues until the end
4382 of the input file. Returns the number of bytes actually copied.
4387 +$handle *filename*+::
4388 Returns the original filename associated with the handle.
4389 Handles returned by `socket` give the socket type instead of a filename.
4392 Returns 1 if stream is at eof
4397 +$handle *seek* 'offset' *?start|current|end?*+::
4398 Seeks in the stream (default 'current')
4401 Returns the current seek position
4403 +$handle *filename*+::
4404 Returns the original filename used when opening the file.
4405 If the handle was returned from `socket`, the type of the
4406 handle is returned instead.
4408 +$handle *ndelay ?0|1?*+::
4409 Set O_NDELAY (if arg). Returns current/new setting.
4410 Note that in general ANSI I/O interacts badly with non-blocking I/O.
4413 +$handle *buffering none|line|full*+::
4414 Sets the buffering mode of the stream.
4416 +$handle *accept*+::
4417 Server socket only: Accept a connection and return stream
4419 +$handle *sendto* 'str ?hostname:?port'+::
4420 Sends the string, +'str'+, to the given address via the socket using sendto(2).
4421 This is intended for udp sockets and may give an error or behave in unintended
4422 ways for other handle types.
4423 Returns the number of bytes written.
4425 +$handle *recvfrom* 'maxlen ?addrvar?'+::
4426 Receives a message from the handle via recvfrom(2) and returns it.
4427 At most +'maxlen'+ bytes are read.
4428 If +'addrvar'+ is specified, the sending address of the message is stored in
4429 the named variable in the form 'addr:port'. See `socket` for details.
4433 +*fconfigure* 'handle' *?-blocking 0|1? ?-buffering noneline|full? ?-translation* 'mode'?+::
4434 For compatibility with Tcl, a limited form of the `fconfigure`
4435 command is supported.
4436 * `fconfigure ... -blocking` maps to `aio ndelay`
4437 * `fconfigure ... -buffering` maps to `aio buffering`
4438 * `fconfigure ... -translation` is accepted but ignored
4441 eventloop: after, vwait, update
4442 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4444 The following commands allow a script to be invoked when the given condition occurs.
4445 If no script is given, returns the current script. If the given script is the empty, the
4448 +$handle *readable* '?readable-script?'+::
4449 Sets or returns the script for when the socket is readable.
4451 +$handle *writable* '?writable-script?'+::
4452 Sets or returns the script for when the socket is writable.
4454 +$handle *onexception* '?exception-script?'+::
4455 Sets or returns the script for when when oob data received.
4457 For compatibility with 'Tcl', these may be prefixed with `fileevent`. e.g.
4460 +fileevent $handle *readable* '\...'+
4462 Time-based execution is also available via the eventloop API.
4465 Sleeps for the given number of milliseconds. No events are
4466 processed during this time.
4468 +*after* 'ms'|*idle* script ?script \...?'+::
4469 The scripts are concatenated and executed after the given
4470 number of milliseconds have elapsed. If 'idle' is specified,
4471 the script will run the next time the event loop is processed
4472 with `vwait` or `update`. The script is only run once and
4473 then removed. Returns an event id.
4475 +*after cancel* 'id|command'+::
4476 Cancels an `after` event with the given event id or matching
4477 command (script). Returns the number of milliseconds
4478 remaining until the event would have fired. Returns the
4479 empty string if no matching event is found.
4481 +*after info* '?id?'+::
4482 If +'id'+ is not given, returns a list of current `after`
4483 events. If +'id'+ is given, returns a list containing the
4484 associated script and either 'timer' or 'idle' to indicated
4485 the type of the event. An error occurs if +'id'+ does not
4488 +*vwait* 'variable'+::
4489 A call to `vwait` is enters the eventloop. `vwait` processes
4490 events until the named (global) variable changes or all
4491 event handlers are removed. The variable need not exist
4492 beforehand. If there are no event handlers defined, `vwait`
4493 returns immediately.
4495 +*update ?idletasks?*+::
4496 A call to `update` enters the eventloop to process expired events, but
4497 no new events. If 'idletasks' is specified, only expired time events are handled,
4499 Returns once handlers have been run for all expired events.
4501 Scripts are executed at the global scope. If an error occurs during a handler script,
4502 an attempt is made to call (the user-defined command) `bgerror` with the details of the error.
4503 If the `bgerror` commands does not exist, it is printed to stderr instead.
4505 If a file event handler script generates an error, the handler is automatically removed
4506 to prevent infinite errors. (A time event handler is always removed after execution).
4508 +*bgerror* 'error'+::
4509 Called when an event handler script generates an error.
4513 Various socket types may be created.
4515 +*socket unix* 'path'+::
4516 A unix domain socket client.
4518 +*socket unix.server* 'path'+::
4519 A unix domain socket server.
4521 +*socket ?-ipv6? stream* 'addr:port'+::
4522 A TCP socket client.
4524 +*socket ?-ipv6? stream.server* '?addr:?port'+::
4525 A TCP socket server (+'addr'+ defaults to +0.0.0.0+ for IPv4 or +[::]+ for IPv6).
4527 +*socket ?-ipv6? dgram* ?'addr:port'?+::
4528 A UDP socket client. If the address is not specified,
4529 the client socket will be unbound and 'sendto' must be used
4530 to indicated the destination.
4532 +*socket ?-ipv6? dgram.server* 'addr:port'+::
4533 A UDP socket server.
4536 A pipe. Note that unlike all other socket types, this command returns
4537 a list of two channels: {read write}
4539 This command creates a socket connected (client) or bound (server) to the given
4542 The returned value is channel and may generally be used with the various file I/O
4543 commands (gets, puts, read, etc.), either as object-based syntax or Tcl-compatible syntax.
4545 set f [socket stream www.google.com:80]
4547 $f puts -nonewline "GET / HTTP/1.0\r\n\r\n"
4552 Server sockets, however support only 'accept', which is most useful in conjunction with
4555 set f [socket stream.server 80]
4557 set client [$f accept]
4560 $client puts -nonewline "HTTP/1.1 404 Not found\r\n"
4565 The address, +'addr'+, can be given in one of the following forms:
4567 1. For IPv4 socket types, an IPv4 address such as 192.168.1.1
4568 2. For IPv6 socket types, an IPv6 address such as [fe80::1234] or [::]
4571 Note that on many systems, listening on an IPv6 address such as [::] will
4572 also accept requests via IPv4.
4574 Where a hostname is specified, the +'first'+ returned address is used
4575 which matches the socket type is used.
4577 The special type 'pipe' isn't really a socket.
4579 lassign [socket pipe] r w
4581 # Must close $w after exec
4589 +*syslog* '?options? ?priority? message'+
4591 This command sends message to system syslog facility with given
4592 priority. Valid priorities are:
4594 emerg, alert, crit, err, error, warning, notice, info, debug
4596 If a message is specified, but no priority is specified, then a
4597 priority of info is used.
4599 By default, facility user is used and the value of global tcl variable
4600 argv0 is used as ident string. However, any of the following options
4601 may be specified before priority to control these parameters:
4603 +*-facility* 'value'+::
4604 Use specified facility instead of user. The following
4605 values for facility are recognized:
4607 authpriv, cron, daemon, kernel, lpr, mail, news, syslog, user,
4610 +*-ident* 'string'+::
4611 Use given string instead of argv0 variable for ident string.
4613 +*-options* 'integer'+::
4614 Set syslog options such as +LOG_CONS+, +LOG_NDELAY+. You should
4615 use numeric values of those from your system syslog.h file,
4616 because I haven't got time to implement yet another hash
4621 The optional 'pack' extension provides commands to encode and decode binary strings.
4623 +*pack* 'varName value' *-intle|-intbe|-str* 'bitwidth ?bitoffset?'+::
4624 Packs the binary representation of +'value'+ into the variable
4625 +'varName'+. The value is packed according to the given type
4626 (integer/string, big-endian/little-endian), width and bit offset.
4627 The variable is created if necessary (like `append`).
4628 Ihe variable is expanded if necessary.
4630 +*unpack* 'binvalue' *-intbe|-intle|-uintbe|-uintle|-str* 'bitpos bitwidth'+::
4631 Unpacks bits from +'binvalue'+ at bit position +'bitpos'+ and with +'bitwidth'+.
4632 Interprets the value according to the type (integer/string, big-endian/little-endian
4633 and signed/unsigned) and returns it. For integer types, +'bitwidth'+
4634 may be up to the size of a Jim Tcl integer (typically 64 bits). For the string type,
4635 both the width and the offset must be on a byte boundary (multiple of 8). Attempting to
4636 access outside the length of the value will return 0 for integer types or the empty string
4637 for the string type.
4641 The optional, pure-Tcl 'binary' extension provides the Tcl-compatible `binary scan` and `binary format`
4642 commands based on the low-level `pack` and `unpack` commands.
4644 See the Tcl documentation at: http://www.tcl.tk/man/tcl8.5/TclCmd/binary.htm
4646 Note that packing and unpacking of floating point values is not supported.
4650 The optional, pure-Tcl 'oo' extension provides object-oriented (OO) support for Jim Tcl.
4652 See the online documentation (http://jim.berlios.de/documentation/oo/) for more details.
4654 +*class* 'classname ?baseclasses? classvars'+::
4655 Create a new class, +'classname'+, with the given dictionary
4656 (+'classvars'+) as class variables. These are the initial variables
4657 which all newly created objects of this class are initialised with.
4658 If a list of baseclasses is given, methods and instance variables
4661 +*super* 'method ?args \...?'+::
4662 From within a method, invokes the given method on the base class.
4663 Note that this will only call the last baseclass given.
4667 The optional, pure-Tcl 'tree' extension implements an OO, general purpose tree structure
4668 similar to that provided by tcllib ::struct::tree (http://tcllib.sourceforge.net/doc/struct_tree.html)
4670 A tree is a collection of nodes, where each node (except the root node) has a single parent
4671 and zero or more child nodes (ordered), as well as zero or more attribute/value pairs.
4674 Creates and returns a new tree object with a single node named "root".
4675 All operations on the tree are invoked through this object.
4678 Destroy the tree and all it's nodes. (Note that the the tree will also
4679 be automatically garbage collected once it goes out of scope).
4681 +$tree *set* 'nodename key value'+::
4682 Set the value for the given attribute key.
4684 +$tree *lappend* 'nodename key value \...'+::
4685 Append to the (list) value(s) for the given attribute key, or set if not yet set.
4687 +$tree *keyexists* 'nodename key'+::
4688 Returns 1 if the given attribute key exists.
4690 +$tree *get* 'nodename key'+::
4691 Returns the value associated with the given attribute key.
4693 +$tree *getall* 'nodename'+::
4694 Returns the entire attribute dictionary associated with the given key.
4696 +$tree *depth* 'nodename'+::
4697 Returns the depth of the given node. The depth of "root" is 0.
4699 +$tree *parent* 'nodename'+::
4700 Returns the node name of the parent node, or "" for the root node.
4702 +$tree *numchildren* 'nodename'+::
4703 Returns the number of child nodes.
4705 +$tree *children* 'nodename'+::
4706 Returns a list of the child nodes.
4708 +$tree *next* 'nodename'+::
4709 Returns the next sibling node, or "" if none.
4711 +$tree *insert* 'nodename ?index?'+::
4712 Add a new child node to the given node. The index is a list index
4713 such as +3+ or +end-2+. The default index is +end+.
4714 Returns the name of the newly added node.
4716 +$tree *walk* 'nodename' *dfs|bfs* {'actionvar nodevar'} 'script'+::
4717 Walks the tree starting from the given node, either breadth first (+bfs+)
4718 depth first (+dfs+).
4719 The value +"enter"+ or +"exit"+ is stored in variable +'actionvar'+.
4720 The name of each node is stored in +'nodevar'+.
4721 The script is evaluated twice for each node, on entry and exit.
4724 Dumps the tree contents to stdout
4726 [[BuiltinVariables]]
4730 The following global variables are created automatically
4734 This variable is set by Jim as an array
4735 whose elements are the environment variables for the process.
4736 Reading an element will return the value of the corresponding
4737 environment variable.
4738 This array is initialised at startup from the `env` command.
4739 It may be modified and will affect the environment passed to
4740 commands invoked with `exec`.
4743 This variable is set by Jim as an array containing information
4744 about the platform on which Jim was built. Currently this includes
4745 'os' and 'platform'.
4748 This variable contains a list of paths to search for packages.
4749 It defaults to a location based on where jim is installed
4750 (e.g. +/usr/local/lib/jim+), but may be changed by +jimsh+
4751 or the embedding application. Note that +jimsh+ will consider
4752 the environment variable +$JIMLIB+ to be a list of colon-separated
4753 list of paths to add to +*auto_path*+.
4756 This variable holds the value of the -errorcode return
4757 option set by the most recent error that occurred in this
4758 interpreter. This list value represents additional information
4759 about the error in a form that is easy to process with
4760 programs. The first element of the list identifies a general
4761 class of errors, and determines the format of the rest of
4762 the list. The following formats for -errorcode return options
4763 are used by the Tcl core; individual applications may define
4764 additional formats. Currently only `exec` sets this variable.
4765 Otherwise it will be +NONE+.
4767 The following global variables are set by jimsh.
4769 +*tcl_interactive*+::
4770 This variable is set to 1 if jimsh is started in interactive mode
4774 This variable is set by Jim as an array containing information
4775 about the platform upon which Jim was built. The following is an
4776 example of the contents of this array.
4778 tcl_platform(byteOrder) = littleEndian
4779 tcl_platform(os) = Darwin
4780 tcl_platform(platform) = unix
4781 tcl_platform(pointerSize) = 8
4782 tcl_platform(threaded) = 0
4783 tcl_platform(wordSize) = 8
4784 tcl_platform(pathSeparator) = :
4787 If jimsh is invoked to run a script, this variable contains the name
4791 If jimsh is invoked to run a script, this variable contains a list
4792 of any arguments supplied to the script.
4795 If jimsh is invoked to run a script, this variable contains the number
4796 of arguments supplied to the script.
4799 The value of argv[0] when jimsh was invoked.
4801 CHANGES IN PREVIOUS RELEASES
4802 ----------------------------
4806 1. `source` now checks that a script is complete (.i.e. not missing a brace)
4807 2. 'info complete' now uses the real parser and so is 100% accurate
4808 3. Better access to live stack frames with 'info frame', `stacktrace` and `stackdump`
4809 4. `tailcall` no longer loses stack trace information
4810 5. Add `alias` and `curry`
4811 6. `lambda`, `alias` and `curry` are implemented via `tailcall` for efficiency
4812 7. `local` allows procedures to be deleted automatically at the end of the current procedure
4813 8. udp sockets are now supported for both clients and servers.
4814 9. vfork-based exec is now working correctly
4815 10. Add 'file tempfile'
4816 11. Add 'socket pipe'
4817 12. Enhance 'try ... on ... finally' to be more Tcl 8.6 compatible
4818 13. It is now possible to `return` from within `try`
4819 14. IPv6 support is now included
4821 16. Event handlers works better if an error occurs. eof handler has been removed.
4822 17. `exec` now sets $::errorCode, and catch sets opts(-errorcode) for exit status
4823 18. Command pipelines via open "|..." are now supported
4824 19. `pid` can now return pids of a command pipeline
4825 20. Add 'info references'
4826 21. Add support for 'after +'ms'+', 'after idle', 'after info', `update`
4827 22. `exec` now sets environment based on $::env
4829 24. Add support for 'lsort -index'
4833 1. Add support to `exec` for '>&', '>>&', '|&', '2>@1'
4834 2. Fix `exec` error messages when special token (e.g. '>') is the last token
4835 3. Fix `subst` handling of backslash escapes.
4836 4. Allow abbreviated options for `subst`
4837 5. Add support for `return`, `break`, `continue` in subst
4838 6. Many `expr` bug fixes
4839 7. Add support for functions in `expr` (e.g. int(), abs()), and also 'in', 'ni' list operations
4840 8. The variable name argument to `regsub` is now optional
4841 9. Add support for 'unset -nocomplain'
4842 10. Add support for list commands: `lassign`, `lrepeat`
4843 11. Fully-functional `lsearch` is now implemented
4844 12. Add 'info nameofexecutable' and 'info returncodes'
4845 13. Allow `catch` to determine what return codes are caught
4846 14. Allow `incr` to increment an unset variable by first setting to 0
4847 15. Allow 'args' and optional arguments to the left or required arguments in `proc`
4849 17. Add 'try ... finally' command
4855 Copyright 2005 Salvatore Sanfilippo <antirez@invece.org>
4856 Copyright 2005 Clemens Hintze <c.hintze@gmx.net>
4857 Copyright 2005 patthoyts - Pat Thoyts <patthoyts@users.sf.net>
4858 Copyright 2008 oharboe - Oyvind Harboe - oyvind.harboe@zylin.com
4859 Copyright 2008 Andrew Lunn <andrew@lunn.ch>
4860 Copyright 2008 Duane Ellis <openocd@duaneellis.com>
4861 Copyright 2008 Uwe Klein <uklein@klein-messgeraete.de>
4862 Copyright 2009 Steve Bennett <steveb@workware.net.au>
4865 Redistribution and use in source and binary forms, with or without
4866 modification, are permitted provided that the following conditions
4868 1. Redistributions of source code must retain the above copyright
4869 notice, this list of conditions and the following disclaimer.
4870 2. Redistributions in binary form must reproduce the above
4871 copyright notice, this list of conditions and the following
4872 disclaimer in the documentation and/or other materials
4873 provided with the distribution.
4875 THIS SOFTWARE IS PROVIDED BY THE JIM TCL PROJECT ``AS IS'' AND ANY
4876 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
4877 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
4878 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
4879 JIM TCL PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
4880 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
4881 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
4882 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
4883 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
4884 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
4885 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
4886 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
4888 The views and conclusions contained in the software and documentation
4889 are those of the authors and should not be interpreted as representing
4890 official policies, either expressed or implied, of the Jim Tcl Project.